NAME¶

srun - Run parallel jobs

SYNOPSIS¶

srun [OPTIONS(0)... [executable(0) [args(0)...]]] [ : [OPTIONS(N)...]] executable(N) [args(N)...]

Option(s) define multiple jobs in a co-scheduled heterogeneous job. For more details about heterogeneous jobs see the document
https://slurm.schedmd.com/heterogeneous_jobs.html

DESCRIPTION¶

Run a parallel job on cluster managed by Slurm. If necessary, srun will first create a resource allocation in which to run the parallel job.

The following document describes the influence of various options on the allocation of cpus to jobs and tasks.
https://slurm.schedmd.com/cpu_management.html

RETURN VALUE¶

srun will return the highest exit code of all tasks run or the highest signal (with the high-order bit set in an 8-bit integer -- e.g. 128 + signal) of any task that exited with a signal.
The value 253 is reserved for out-of-memory errors.

EXECUTABLE PATH RESOLUTION¶

The executable is resolved in the following order:

1. If executable starts with ".", then path is constructed as: current working directory / executable
2. If executable starts with a "/", then path is considered absolute.
3. If executable can be resolved through PATH. See path_resolution(7).
4. If executable is in current working directory.

Current working directory is the calling process working directory unless the --chdir argument is passed, which will override the current working directory.

OPTIONS¶

-A, --account=<account>

Charge resources used by this job to specified account. The account is an arbitrary string. The account name may be changed after job submission using the scontrol command. This option applies to job allocations.

--acctg-freq=<datatype>=<interval>[,<datatype>=<interval>...]

Define the job accounting and profiling sampling intervals in seconds. This can be used to override the JobAcctGatherFrequency parameter in the slurm.conf file. <datatype>=<interval> specifies the task sampling interval for the jobacct_gather plugin or a sampling interval for a profiling type by the acct_gather_profile plugin. Multiple comma-separated <datatype>=<interval> pairs may be specified. Supported datatype values are:

--bb=<spec>

Burst buffer specification. The form of the specification is system dependent. Also see --bbf. This option applies to job allocations. When the --bb option is used, Slurm parses this option and creates a temporary burst buffer script file that is used internally by the burst buffer plugins. See Slurm's burst buffer guide for more information and examples:
https://slurm.schedmd.com/burst_buffer.html

--bbf=<file_name>

Path of file containing burst buffer specification. The form of the specification is system dependent. Also see --bb. This option applies to job allocations. See Slurm's burst buffer guide for more information and examples:
https://slurm.schedmd.com/burst_buffer.html

--bcast[=<dest_path>]

Copy executable file to allocated compute nodes. If a file name is specified, copy the executable to the specified destination file path. If the path specified ends with '/' it is treated as a target directory, and the destination file name will be slurm_bcast_<job_id>.<step_id>_<nodename>. If no dest_path is specified and the slurm.conf BcastParameters DestDir is configured then it is used, and the filename follows the above pattern. If none of the previous is specified, then --chdir is used, and the filename follows the above pattern too. For example, "srun --bcast=/tmp/mine -N3 a.out" will copy the file "a.out" from your current directory to the file "/tmp/mine" on each of the three allocated compute nodes and execute that file. This option applies to step allocations.

--bcast-exclude={NONE|<exclude_path>[,<exclude_path>...]}

Comma-separated list of absolute directory paths to be excluded when autodetecting and broadcasting executable shared object dependencies through --bcast. If the keyword "NONE" is configured, no directory paths will be excluded. The default value is that of slurm.conf BcastExclude and this option overrides it. See also --bcast and --send-libs.

-b, --begin=<time>

Defer initiation of this job until the specified time. It accepts times of the form HH:MM:SS to run a job at a specific time of day (seconds are optional). (If that time is already past, the next day is assumed.) You may also specify midnight, noon, elevenses (11 AM), fika (3 PM) or teatime (4 PM) and you can have a time-of-day suffixed with AM or PM for running in the morning or the evening. You can also say what day the job will be run, by specifying a date of the form MMDDYY or MM/DD/YY YYYY-MM-DD. Combine date and time using the following format YYYY-MM-DD[THH:MM[:SS]]. You can also give times like now + count time-units, where the time-units can be seconds (default), minutes, hours, days, or weeks and you can tell Slurm to run the job today with the keyword today and to run the job tomorrow with the keyword tomorrow. The value may be changed after job submission using the scontrol command. For example:

   --begin=16:00


   --begin=now+1hour


   --begin=now+60           (seconds by default)


   --begin=2010-01-20T12:34:00

-D, --chdir=<path>

Have the remote processes do a chdir to path before beginning execution. The default is to chdir to the current working directory of the srun process. The path can be specified as full path or relative path to the directory where the command is executed. This option applies to job allocations.

--cluster-constraint=<list>

Specifies features that a federated cluster must have to have a sibling job submitted to it. Slurm will attempt to submit a sibling job to a cluster if it has at least one of the specified features.

-M, --clusters=<string>

Clusters to issue commands to. Multiple cluster names may be comma separated. The job will be submitted to the one cluster providing the earliest expected job initiation time. The default value is the current cluster. A value of 'all' will query to run on all clusters. Note the --export option to control environment variables exported between clusters. This option applies only to job allocations. Note that the slurmdbd must be up for this option to work properly, unless running in a federation with FederationParameters=fed_display configured.

--comment=<string>

An arbitrary comment. This option applies to job allocations.

--compress[=type]

Compress file before sending it to compute hosts. The optional argument specifies the data compression library to be used. The default is BcastParameters Compression= if set or "lz4" otherwise. Supported values are "lz4". Some compression libraries may be unavailable on some systems. For use with the --bcast option. This option applies to step allocations.

-C, --constraint=<list>

Nodes can have features assigned to them by the Slurm administrator. Users can specify which of these features are required by their job using the constraint option. If you are looking for 'soft' constraints please see --prefer for more information. Only nodes having features matching the job constraints will be used to satisfy the request. Multiple constraints may be specified with AND, OR, matching OR, resource counts, etc. (some operators are not supported on all system types).

NOTE: Changeable features are features defined by a NodeFeatures plugin.

Supported --constraint options include:

--container=<path_to_container>

Absolute path to OCI container bundle.

--container-id=<container_id>

Unique name for OCI container.

--contiguous

If set, then the allocated nodes must form a contiguous set.

NOTE: If the SelectType is cons_tres this option won't be honored with the topology/tree or topology/3d_torus plugins, both of which can modify the node ordering. This option applies to job allocations.

-S, --core-spec=<num>

Count of Specialized Cores per node reserved by the job for system operations and not used by the application. If AllowSpecResourcesUsage is enabled a job can override the CoreSpecCount of all its allocated nodes with this option. The overridden Specialized Cores will still be reserved for system processes. The job will get an implicit --exclusive allocation for the rest of the Cores on the nodes, resulting in the job's processes being able to use (and being charged for) all the Cores on the nodes except for the overridden Specialized Cores. This option can not be used with the --thread-spec option.

NOTE: Explicitly setting a job's specialized core value implicitly sets the --exclusive option.

NOTE: This option may implicitly impact the number of tasks if -n was not specified.

This option applies to job allocations.

--cores-per-socket=<cores>

Restrict node selection to nodes with at least the specified number of cores per socket. See additional information under -B option above when task/affinity plugin is enabled. This option applies to job allocations.

--cpu-bind=[{quiet|verbose},]<type>

Bind tasks to CPUs. Used only when the task/affinity plugin is enabled. NOTE: To have Slurm always report on the selected CPU binding for all commands executed in a shell, you can enable verbose mode by setting the SLURM_CPU_BIND environment variable value to "verbose".

The following informational environment variables are set when --cpu-bind is in use:

	SLURM_CPU_BIND_VERBOSE
	SLURM_CPU_BIND_TYPE
	SLURM_CPU_BIND_LIST

See the ENVIRONMENT VARIABLES section for a more detailed description of the individual SLURM_CPU_BIND variables. These variables are available only if the task/affinity plugin is configured.

When using --cpus-per-task to run multithreaded tasks, be aware that CPU binding is inherited from the parent of the process. This means that the multithreaded task should either specify or clear the CPU binding itself to avoid having all threads of the multithreaded task use the same mask/CPU as the parent. Alternatively, fat masks (masks which specify more than one allowed CPU) could be used for the tasks in order to provide multiple CPUs for the multithreaded tasks.

Note that a job step can be allocated different numbers of CPUs on each node or be allocated CPUs not starting at location zero. Therefore one of the options which automatically generate the task binding is recommended. Explicitly specified masks or bindings are only honored when the job step has been allocated every available CPU on the node.

Binding a task to a NUMA locality domain means to bind the task to the set of CPUs that belong to the NUMA locality domain or "NUMA node". If NUMA locality domain options are used on systems with no NUMA support, then each socket is considered a locality domain.

If the --cpu-bind option is not used, the default binding mode will depend upon Slurm's configuration and the step's resource allocation. If all allocated nodes have the same configured CpuBind mode, that will be used. Otherwise if the job's Partition has a configured CpuBind mode, that will be used. Otherwise if Slurm has a configured TaskPluginParam value, that mode will be used. Otherwise automatic binding will be performed as described below.

--cpu-freq=<p1>[-p2][:p3]

Request that the job step initiated by this srun command be run at some requested frequency if possible, on the CPUs selected for the step on the compute node(s).

p1 can be [#### | low | medium | high | highm1] which will set the frequency scaling_speed to the corresponding value, and set the frequency scaling_governor to UserSpace. See below for definition of the values.

p1 can be [Conservative | OnDemand | Performance | PowerSave] which will set the scaling_governor to the corresponding value. The governor has to be in the list set by the slurm.conf option CpuFreqGovernors.

When p2 is present, p1 will be the minimum scaling frequency and p2 will be the maximum scaling frequency. In that case the governor p3 or CpuFreqDef cannot be UserSpace since it doesn't support a range.

p2 can be [#### | medium | high | highm1]. p2 must be greater than p1 and is incompatible with UserSpace governor.

p3 can be [Conservative | OnDemand | Performance | PowerSave | SchedUtil | UserSpace] which will set the governor to the corresponding value.

If p3 is UserSpace, the frequency scaling_speed, scaling_max_freq and scaling_min_freq will be statically set to the value defined by p1.

Any requested frequency below the minimum available frequency will be rounded to the minimum available frequency. In the same way, any requested frequency above the maximum available frequency will be rounded to the maximum available frequency.

The CpuFreqDef parameter in slurm.conf will be used to set the governor in absence of p3. If there's no CpuFreqDef, the default governor will be to use the system current governor set in each cpu. Specifying a range without CpuFreqDef or a specific governor is therefore not allowed.

Acceptable values at present include:

The following informational environment variable is set in the job step when --cpu-freq option is requested.

        SLURM_CPU_FREQ_REQ

This environment variable can also be used to supply the value for the CPU frequency request if it is set when the 'srun' command is issued. The --cpu-freq on the command line will override the environment variable value. The form on the environment variable is the same as the command line. See the ENVIRONMENT VARIABLES section for a description of the SLURM_CPU_FREQ_REQ variable.

NOTE: This parameter is treated as a request, not a requirement. If the job step's node does not support setting the CPU frequency, or the requested value is outside the bounds of the legal frequencies, an error is logged, but the job step is allowed to continue.

NOTE: Setting the frequency for just the CPUs of the job step implies that the tasks are confined to those CPUs. If task confinement (i.e. the task/affinity TaskPlugin is enabled, or the task/cgroup TaskPlugin is enabled with "ConstrainCores=yes" set in cgroup.conf) is not configured, this parameter is ignored.

NOTE: When the step completes, the frequency and governor of each selected CPU is reset to the previous values.

NOTE: When submitting jobs with the --cpu-freq option with linuxproc as the ProctrackType can cause jobs to run too quickly before Accounting is able to poll for job information. As a result not all of accounting information will be present.

This option applies to job and step allocations.

--cpus-per-gpu=<ncpus>

Request that ncpus processors be allocated per allocated GPU. This option implies --exact. Not compatible with the --cpus-per-task option.

This option applies to job and step allocations.

-c, --cpus-per-task=<ncpus>

Request that ncpus be allocated per process. This may be useful if the job is multithreaded and requires more than one CPU per task for optimal performance. Explicitly requesting this option implies --exact. The default is one CPU per process and does not imply --exact. If -c is specified without -n, as many tasks will be allocated per node as possible while satisfying the -c restriction. For instance on a cluster with 8 CPUs per node, a job request for 4 nodes and 3 CPUs per task may be allocated 3 or 6 CPUs per node (1 or 2 tasks per node) depending upon resource consumption by other jobs. Such a job may be unable to execute more than a total of 4 tasks.

WARNING: There are configurations and options interpreted differently by job and job step requests which can result in inconsistencies for this option. For example srun -c2 --threads-per-core=1 prog may allocate two cores for the job, but if each of those cores contains two threads, the job allocation will include four CPUs. The job step allocation will then launch two threads per CPU for a total of two tasks.

WARNING: When srun is executed from within salloc or sbatch, there are configurations and options which can result in inconsistent allocations when -c has a value greater than -c on salloc or sbatch.

NOTE: If --mem-per-cpu is also specified, the number of allocated cpus can be increased if MaxMemPerCPU is exceeded. In the case -n is not specified, the number of tasks can be higher than expected.

This option applies to job and step allocations.

--deadline=<OPT>

Remove the job if no ending is possible before this deadline (start > (deadline - time[-min])). Default is no deadline. Note that if neither DefaultTime nor MaxTime are configured on the partition the job is in, the job will need to specify some form of time limit (--time[-min]) if a deadline is to be used.

Valid time formats are:
HH:MM[:SS] [AM|PM]
MMDD[YY] or MM/DD[/YY] or MM.DD[.YY]
MM/DD[/YY]-HH:MM[:SS]
YYYY-MM-DD[THH:MM[:SS]]]
now[+count[seconds(default)|minutes|hours|days|weeks]]

This option applies only to job allocations.

--delay-boot=<minutes>

Do not reboot nodes in order to satisfied this job's feature specification if the job has been eligible to run for less than this time period. If the job has waited for less than the specified period, it will use only nodes which already have the specified features. The argument is in units of minutes. A default value may be set by a system administrator using the delay_boot option of the SchedulerParameters configuration parameter in the slurm.conf file, otherwise the default value is zero (no delay).

This option applies only to job allocations.

-d, --dependency=<dependency_list>

Defer the start of this job until the specified dependencies have been satisfied. Once a dependency is satisfied, it is removed from the job. This option does not apply to job steps (executions of srun within an existing salloc or sbatch allocation) only to job allocations. <dependency_list> is of the form <type:job_id[:job_id][,type:job_id[:job_id]]> or <type:job_id[:job_id][?type:job_id[:job_id]]>. All dependencies must be satisfied if the "," separator is used. Any dependency may be satisfied if the "?" separator is used. Only one separator may be used. For instance:

-d afterok:20:21,afterany:23

means that the job can run only after a 0 return code of jobs 20 and 21 AND the completion of job 23. However:

-d afterok:20:21?afterany:23

means that any of the conditions (afterok:20 OR afterok:21 OR afterany:23) will be enough to release the job. Many jobs can share the same dependency and these jobs may even belong to different users. The value may be changed after job submission using the scontrol command. Dependencies on remote jobs are allowed in a federation. Once a job dependency fails due to the termination state of a preceding job, the dependent job will never be run, even if the preceding job is requeued and has a different termination state in a subsequent execution. This option applies to job allocations.

-X, --disable-status

Disable the display of task status when srun receives a single SIGINT (Ctrl-C). Instead immediately forward the SIGINT to the running job. Without this option a second Ctrl-C in one second is required to forcibly terminate the job and srun will immediately exit. May also be set via the environment variable SLURM_DISABLE_STATUS. This option applies to job allocations.

-m, --distribution={*|block|cyclic|arbitrary|plane=<size>}[:{*|block|cyclic|fcyclic}[:{*|block|cyclic|fcyclic}]][,{Pack|NoPack}]

Specify alternate distribution methods for remote processes. For job allocation, this sets environment variables that will be used by subsequent srun requests. Task distribution affects job allocation at the last stage of the evaluation of available resources by the cons_tres plugin. Consequently, other options (e.g. --ntasks-per-node, --cpus-per-task) may affect resource selection prior to task distribution. To ensure a specific task distribution, jobs should have access to entire nodes, which can be accomplished by using the --exclusive flag or by requesting all the resources on the node(s).

This option controls the distribution of tasks to the nodes on which resources have been allocated, and the distribution of those resources to tasks for binding (task affinity). The first distribution method (before the first ":") controls the distribution of tasks to nodes. The second distribution method (after the first ":") controls the distribution of allocated CPUs across sockets for binding to tasks. The third distribution method (after the second ":") controls the distribution of allocated CPUs across cores for binding to tasks. The second and third distributions apply only if task affinity is enabled. The third distribution is supported only if the task/cgroup plugin is configured. The default value for each distribution type is specified by *.

Note that with select/cons_tres, the number of CPUs allocated to each socket and node may be different. Refer to https://slurm.schedmd.com/mc_support.html for more information on resource allocation, distribution of tasks to nodes, and binding of tasks to CPUs.

--epilog={none|<executable>}

srun will run executable just after the job step completes. The command line arguments for executable will be the command and arguments of the job step. If none is specified, then no srun epilog will be run. This parameter overrides the SrunEpilog parameter in slurm.conf. This parameter is completely independent from the Epilog parameter in slurm.conf. This option applies to job allocations.

-e, --error=<filename_pattern>

Specify how stderr is to be redirected. By default in interactive mode, srun redirects stderr to the same file as stdout, if one is specified. The --error option is provided to allow stdout and stderr to be redirected to different locations. See IO Redirection below for more options. If the specified file already exists, it will be overwritten. This option applies to job and step allocations.

--exact

Allow a step access to only the resources requested for the step. By default, all non-GRES resources on each node in the step allocation will be used. This option only applies to step allocations.
NOTE: Parallel steps will either be blocked or rejected until requested step resources are available unless --overlap is specified. Job resources can be held after the completion of an srun command while Slurm does job cleanup. Step epilogs and/or SPANK plugins can further delay the release of step resources.

-x, --exclude={<host1[,<host2>...]|<filename>}

Request that a specific list of hosts not be included in the resources allocated to this job. The host list will be assumed to be a filename if it contains a "/" character. This option applies to job and step allocations.

--exclusive[={user|mcs|topo}]

This option applies to job and job step allocations, and has two slightly different meanings for each one.

When used to initiate a job, the job allocation can not share nodes (or topology segment with the "=topo") with other running jobs (or just other users with the "=user" option or "=mcs" option). If user/mcs/topo are not specified (i.e. the job allocation can not share nodes with other running jobs), the job allocation is allocated all CPUs and GRES on all nodes in the allocation, but is only allocated as much memory as it requested. This is by design to support gang scheduling, because suspended jobs still reside in memory. To request all the memory on a node, use --mem=0. The default shared/exclusive behavior depends on system configuration and the partition's OverSubscribe option takes precedence over the job's option. NOTE: Since shared GRES (MPS) cannot be allocated at the same time as a sharing GRES (GPU) this option only allocates all sharing GRES and no underlying shared GRES.

This option can also be used when initiating more than one job step within an existing resource allocation (default), where you want separate processors to be dedicated to each job step. The job step is only allocated as much GRES as is requested. If sufficient processors are not available to initiate the job step, it will be deferred. This can be thought of as providing a mechanism for resource management to the job within its allocation (--exact implied). The exclusive allocation of CPUs applies to job steps by default, but --exact is NOT the default. In other words, the default behavior is this: job steps will not share CPUs, but job steps will be allocated all CPUs available to the job on all nodes allocated to the steps.

In order to share the resources use the --overlap option.

NOTE: This option is mutually exclusive with --oversubscribe.

See EXAMPLE below.

--export={[ALL,]<environment_variables>|ALL|NONE}

Identify which environment variables from the submission environment are propagated to the launched application.

--external-launcher

Create a special step on one or more allocated nodes which won't consume any resources, but will have access to all of the job's allocated resources on the nodes.

Options like --ntasks-per-*, --mem*, --cpus*, --tres*, --gres*, will be ignored.

This is meant for use MPI implementations that require their own launcher. This launches a step with access to all the resources and which will later spawn any number of user processes with access to all these resources.

The resource usage within this special step will still be accounted for if the accounting plugins are enabled. This special step can be overlapped with any other step.

NOTE: This option is not intended to be used directly.

--extra=<string>

An arbitrary string enclosed in single or double quotes if using spaces or some special characters.

If SchedulerParameters=extra_constraints is enabled, this string is used for node filtering based on the Extra field in each node.

-B, --extra-node-info=<sockets>[:cores[:threads]]

Restrict node selection to nodes with at least the specified number of sockets, cores per socket and/or threads per core.
NOTE: These options do not specify the resource allocation size. Each value specified is considered a minimum. An asterisk (*) can be used as a placeholder indicating that all available resources of that type are to be utilized. Values can also be specified as min-max. The individual levels can also be specified in separate options if desired:

    --sockets-per-node=<sockets>


    --cores-per-socket=<cores>


    --threads-per-core=<threads>

If task/affinity plugin is enabled, then specifying an allocation in this manner also sets a default --cpu-bind option of threads if the -B option specifies a thread count, otherwise an option of cores if a core count is specified, otherwise an option of sockets. If SelectType is configured to select/cons_tres, it must have a parameter of CR_Core, CR_Core_Memory, CR_Socket, or CR_Socket_Memory for this option to be honored. If not specified, the scontrol show job will display 'ReqS:C:T=*:*:*'. This option applies to job allocations.
NOTE: This option is mutually exclusive with --hint, --threads-per-core and --ntasks-per-core.
NOTE: If the number of sockets, cores and threads were all specified, the number of nodes was specified (as a fixed number, not a range) and the number of tasks was NOT specified, srun will implicitly calculate the number of tasks as one task per thread.

--gpu-bind=[verbose,]<type>

Equivalent to --tres-bind=gres/gpu:[verbose,]<type> See --tres-bind for all options and documentation.

--gpu-freq=[<type]=value>[,<type=value>][,verbose]

Request that GPUs allocated to the job are configured with specific frequency values. This option can be used to independently configure the GPU and its memory frequencies. After the job is completed, the frequencies of all affected GPUs will be reset to the highest possible values. In some cases, system power caps may override the requested values. The field type can be "memory". If type is not specified, the GPU frequency is implied. The value field can either be "low", "medium", "high", "highm1" or a numeric value in megahertz (MHz). If the specified numeric value is not possible, a value as close as possible will be used. See below for definition of the values. The verbose option causes current GPU frequency information to be logged. Examples of use include "--gpu-freq=medium,memory=high" and "--gpu-freq=450".

Supported value definitions:

-G, --gpus=[type:]<number>

Specify the total number of GPUs required for the job. An optional GPU type specification can be supplied. See also the --gpus-per-node, --gpus-per-socket and --gpus-per-task options.
NOTE: The allocation has to contain at least one GPU per node, or one of each GPU type per node if types are used. Use heterogeneous jobs if different nodes need different GPU types.

--gpus-per-node=[type:]<number>

Specify the number of GPUs required for the job on each node included in the job's resource allocation. An optional GPU type specification can be supplied. For example "--gpus-per-node=volta:3". Multiple options can be requested in a comma separated list, for example: "--gpus-per-node=volta:3,kepler:1". See also the --gpus, --gpus-per-socket and --gpus-per-task options.

--gpus-per-socket=[type:]<number>

Specify the number of GPUs required for the job on each socket included in the job's resource allocation. An optional GPU type specification can be supplied. For example "--gpus-per-socket=volta:3". Multiple options can be requested in a comma separated list, for example: "--gpus-per-socket=volta:3,kepler:1". Requires job to specify a sockets per node count ( --sockets-per-node). See also the --gpus, --gpus-per-node and --gpus-per-task options. This option applies to job allocations.

--gpus-per-task=[type:]<number>

Specify the number of GPUs required for the job on each task to be spawned in the job's resource allocation. An optional GPU type specification can be supplied. For example "--gpus-per-task=volta:1". Multiple options can be requested in a comma separated list, for example: "--gpus-per-task=volta:3,kepler:1". See also the --gpus, --gpus-per-socket and --gpus-per-node options. This option requires an explicit task count, e.g. -n, --ntasks or "--gpus=X --gpus-per-task=Y" rather than an ambiguous range of nodes with -N, --nodes. This option will implicitly set --tres-bind=gres/gpu:per_task:<gpus_per_task>, but that can be overridden with an explicit --tres-bind=gres/gpu specification.

--gres=<list>

Specifies a comma-delimited list of generic consumable resources. The format for each entry in the list is "name[[:type]:count]". The name is the type of consumable resource (e.g. gpu). The type is an optional classification for the resource (e.g. a100). The count is the number of those resources with a default value of 1. The count can have a suffix of "k" or "K" (multiple of 1024), "m" or "M" (multiple of 1024 x 1024), "g" or "G" (multiple of 1024 x 1024 x 1024), "t" or "T" (multiple of 1024 x 1024 x 1024 x 1024), "p" or "P" (multiple of 1024 x 1024 x 1024 x 1024 x 1024). The specified resources will be allocated to the job on each node. The available generic consumable resources is configurable by the system administrator. A list of available generic consumable resources will be printed and the command will exit if the option argument is "help". Examples of use include "--gres=gpu:2", "--gres=gpu:kepler:2", and "--gres=help". NOTE: This option applies to job and step allocations. By default, a job step is allocated all of the generic resources that have been requested by the job, except those implicitly requested when a job is exclusive. To change the behavior so that each job step is allocated no generic resources, explicitly set the value of --gres to specify zero counts for each generic resource OR set "--gres=none" OR set the SLURM_STEP_GRES environment variable to "none".

--gres-flags=<type>

Specify generic resource task binding options.

-h, --help

Display help information and exit.

--het-group=<expr>

Identify each component in a heterogeneous job allocation for which a step is to be created. Applies only to srun commands issued inside a salloc allocation or sbatch script. <expr> is a set of integers corresponding to one or more options offsets on the salloc or sbatch command line. Examples: "--het-group=2", "--het-group=0,4", "--het-group=1,3-5". The default value is --het-group=0.

--hint=<type>

Bind tasks according to application hints.
NOTE: This option implies specific values for certain related options, which prevents its use with any user-specified values for --ntasks-per-core, --threads-per-core, --cpu-bind (other than --cpu-bind=verbose) or -B. These conflicting options will override --hint when specified as command line arguments. If a conflicting option is specified as an environment variable, --hint as a command line argument will take precedence.

-H, --hold

Specify the job is to be submitted in a held state (priority of zero). A held job can now be released using scontrol to reset its priority (e.g. "scontrol release <job_id>"). This option applies to job allocations.

-I, --immediate[=<seconds>]

exit if resources are not available within the time period specified. If no argument is given (seconds defaults to 1), resources must be available immediately for the request to succeed. If defer is configured in SchedulerParameters and seconds=1 the allocation request will fail immediately; defer conflicts and takes precedence over this option. By default, --immediate is off, and the command will block until resources become available. Since this option's argument is optional, for proper parsing the single letter option must be followed immediately with the value and not include a space between them. For example "-I60" and not "-I 60". This option applies to job and step allocations.

-i, --input=<mode>

Specify how stdin is to be redirected. By default, srun redirects stdin from the terminal to all tasks. See IO Redirection below for more options. For OS X, the poll() function does not support stdin, so input from a terminal is not possible. This option applies to job and step allocations.

-J, --job-name=<jobname>

Specify a name for the job. The specified name will appear along with the job id number when querying running jobs on the system. The default is the supplied executable program's name. NOTE: This information may be written to the slurm_jobacct.log file. This file is space delimited so if a space is used in the jobname name it will cause problems in properly displaying the contents of the slurm_jobacct.log file when the sacct command is used. This option applies to job and step allocations.

--jobid=<jobid>

Initiate a job step under an already allocated job with job id id. Using this option will cause srun to behave exactly as if the SLURM_JOB_ID environment variable was set. This option applies to step allocations.

-K, --kill-on-bad-exit[=0|1]

Controls whether or not to terminate a step if any task exits with a non-zero exit code. If this option is not specified, the default action will be based upon the Slurm configuration parameter of KillOnBadExit. If this option is specified, it will take precedence over KillOnBadExit. An option argument of zero will not terminate the job. A non-zero argument or no argument will terminate the job. Note: This option takes precedence over the -W, --wait option to terminate the job immediately if a task exits with a non-zero exit code. Since this option's argument is optional, for proper parsing the single letter option must be followed immediately with the value and not include a space between them. For example "-K1" and not "-K 1".

-l, --label

Prepend task number to lines of stdout/err. The --label option will prepend lines of output with the remote task id. This option applies to step allocations.

-L, --licenses=<license>[@db][:count][,license[@db][:count]...]

Specification of licenses (or other resources available on all nodes of the cluster) which must be allocated to this job. License names can be followed by a colon and count (the default count is one). Multiple license names should be comma separated (e.g. "--licenses=foo:4,bar"). This option applies to job allocations.

NOTE: When submitting heterogeneous jobs, license requests may only be made on the first component job. For example "srun -L ansys:2 : myexecutable".

--mail-type=<type>

Notify user by email when certain event types occur. Valid type values are NONE, BEGIN, END, FAIL, REQUEUE, ALL (equivalent to BEGIN, END, FAIL, INVALID_DEPEND, REQUEUE, and STAGE_OUT), INVALID_DEPEND (dependency never satisfied), STAGE_OUT (burst buffer stage out and teardown completed), TIME_LIMIT, TIME_LIMIT_90 (reached 90 percent of time limit), TIME_LIMIT_80 (reached 80 percent of time limit), and TIME_LIMIT_50 (reached 50 percent of time limit). Multiple type values may be specified in a comma separated list. NONE will suppress all event notifications, ignoring any other values specified. By default no email notifications are sent. The user to be notified is indicated with --mail-user. This option applies to job allocations.

--mail-user=<user>

User to receive email notification of state changes as defined by --mail-type. This may be a full email address or a username. If a username is specified, the value from MailDomain in slurm.conf will be appended to create an email address. The default value is the submitting user. This option applies to job allocations.

--mcs-label=<mcs>

Used only when the mcs/group plugin is enabled. This parameter is a group among the groups of the user. Default value is calculated by the Plugin mcs if it's enabled. This option applies to job allocations.

--mem=<size>[units]

Specify the real memory required per node. Default units are megabytes. Different units can be specified using the suffix [K|M|G|T]. Default value is DefMemPerNode and the maximum value is MaxMemPerNode. If configured, both of parameters can be seen using the scontrol show config command. This parameter would generally be used if whole nodes are allocated to jobs (SelectType=select/linear). Specifying a memory limit of zero for a job step will restrict the job step to the amount of memory allocated to the job, but not remove any of the job's memory allocation from being available to other job steps. Also see --mem-per-cpu and --mem-per-gpu. The --mem, --mem-per-cpu and --mem-per-gpu options are mutually exclusive. If --mem, --mem-per-cpu or --mem-per-gpu are specified as command line arguments, then they will take precedence over the environment (potentially inherited from salloc or sbatch).

NOTE: A memory size specification of zero is treated as a special case and grants the job access to all of the memory on each node for newly submitted jobs and all available job memory to new job steps.

NOTE: Memory requests will not be strictly enforced unless Slurm is configured to use an enforcement mechanism. See ConstrainRAMSpace in the cgroup.conf(5) man page and OverMemoryKill in the slurm.conf(5) man page for more details.

This option applies to job and step allocations.

--mem-bind=[{quiet|verbose},]<type>

Bind tasks to memory. Used only when the task/affinity plugin is enabled and the NUMA memory functions are available. Note that the resolution of CPU and memory binding may differ on some architectures. For example, CPU binding may be performed at the level of the cores within a processor while memory binding will be performed at the level of nodes, where the definition of "nodes" may differ from system to system. By default no memory binding is performed; any task using any CPU can use any memory. This option is typically used to ensure that each task is bound to the memory closest to its assigned CPU. The use of any type other than "none" or "local" is not recommended. If you want greater control, try running a simple test code with the options "--cpu-bind=verbose,none --mem-bind=verbose,none" to determine the specific configuration.

NOTE: To have Slurm always report on the selected memory binding for all commands executed in a shell, you can enable verbose mode by setting the SLURM_MEM_BIND environment variable value to "verbose".

The following informational environment variables are set when --mem-bind is in use:

	SLURM_MEM_BIND_LIST
	SLURM_MEM_BIND_PREFER
	SLURM_MEM_BIND_SORT
	SLURM_MEM_BIND_TYPE
	SLURM_MEM_BIND_VERBOSE

See the ENVIRONMENT VARIABLES section for a more detailed description of the individual SLURM_MEM_BIND* variables.

Supported options include:

--mem-per-cpu=<size>[units]

Minimum memory required per usable allocated CPU. Default units are megabytes. Different units can be specified using the suffix [K|M|G|T]. The default value is DefMemPerCPU and the maximum value is MaxMemPerCPU (see exception below). If configured, both parameters can be seen using the scontrol show config command. Note that if the job's --mem-per-cpu value exceeds the configured MaxMemPerCPU, then the user's limit will be treated as a memory limit per task; --mem-per-cpu will be reduced to a value no larger than MaxMemPerCPU; --cpus-per-task will be set and the value of --cpus-per-task multiplied by the new --mem-per-cpu value will equal the original --mem-per-cpu value specified by the user. If the user already specified a value for --cpus-per-task, it will be respected and only the total amount of allocated CPUs will change. This parameter would generally be used if individual processors are allocated to jobs (SelectType=select/cons_tres). If resources are allocated by core, socket, or whole nodes, then the number of CPUs allocated to a job may be higher than the task count and the value of --mem-per-cpu should be adjusted accordingly. Specifying a memory limit of zero for a job step will restrict the job step to the amount of memory allocated to the job, but not remove any of the job's memory allocation from being available to other job steps. Also see --mem and --mem-per-gpu. The --mem, --mem-per-cpu and --mem-per-gpu options are mutually exclusive.

NOTE: If the final amount of memory requested by a job can't be satisfied by any of the nodes configured in the partition, the job will be rejected. This could happen if --mem-per-cpu is used with the --exclusive option for a job allocation and --mem-per-cpu times the number of CPUs on a node is greater than the total memory of that node.

NOTE: This applies to usable allocated CPUs in a job allocation. This is important when more than one thread per core is configured. If a job requests --threads-per-core with fewer threads on a core than exist on the core (or --hint=nomultithread which implies --threads-per-core=1), the job will be unable to use those extra threads on the core and those threads will not be included in the memory per CPU calculation. But if the job has access to all threads on the core, those threads will be included in the memory per CPU calculation even if the job did not explicitly request those threads.

In the following examples, each core has two threads.

In this first example, two tasks can run on separate hyperthreads in the same core because --threads-per-core is not used. The third task uses both threads of the second core. The allocated memory per cpu includes all threads:

$ salloc -n3 --mem-per-cpu=100
salloc: Granted job allocation 17199
$ sacct -j $SLURM_JOB_ID -X -o jobid%7,reqtres%35,alloctres%35


  JobID                             ReqTRES                           AllocTRES
------- ----------------------------------- -----------------------------------


  17199     billing=3,cpu=3,mem=300M,node=1     billing=4,cpu=4,mem=400M,node=1
    

In this second example, because of --threads-per-core=1, each task is allocated an entire core but is only able to use one thread per core. Allocated CPUs includes all threads on each core. However, allocated memory per cpu includes only the usable thread in each core.

$ salloc -n3 --mem-per-cpu=100 --threads-per-core=1
salloc: Granted job allocation 17200
$ sacct -j $SLURM_JOB_ID -X -o jobid%7,reqtres%35,alloctres%35


  JobID                             ReqTRES                           AllocTRES
------- ----------------------------------- -----------------------------------


  17200     billing=3,cpu=3,mem=300M,node=1     billing=6,cpu=6,mem=300M,node=1
    

--mem-per-gpu=<size>[units]

Minimum memory required per allocated GPU. Default units are megabytes. Different units can be specified using the suffix [K|M|G|T]. Default value is DefMemPerGPU and is available on both a global and per partition basis. If configured, the parameters can be seen using the scontrol show config and scontrol show partition commands. Also see --mem. The --mem, --mem-per-cpu and --mem-per-gpu options are mutually exclusive.

--mincpus=<n>

Specify a minimum number of logical cpus/processors per node. This option applies to job allocations.

--mpi=<mpi_type>

Identify the type of MPI to be used. May result in unique initiation procedures.

--msg-timeout=<seconds>

Modify the job launch message timeout. The default value is MessageTimeout in the Slurm configuration file slurm.conf. Changes to this are typically not recommended, but could be useful to diagnose problems. This option applies to job allocations.

--multi-prog

Run a job with different programs and different arguments for each task. In this case, the executable program specified is actually a configuration file specifying the executable and arguments for each task. See MULTIPLE PROGRAM CONFIGURATION below for details on the configuration file contents. This option applies to step allocations.

--network=<type>

Specify information pertaining to the switch or network. The interpretation of type is system dependent. This option is supported when running Slurm on a Cray natively. It is used to request using Network Performance Counters. Only one value per request is valid. All options are case in-sensitive. In this configuration supported values include:

In all cases the job allocation request must specify the --exclusive option and the step cannot specify the --overlap option. Otherwise the request will be denied.

Also with any of these options steps are not allowed to share blades, so resources would remain idle inside an allocation if the step running on a blade does not take up all the nodes on the blade.

The network option is also available on systems with HPE Slingshot networks. It can be used to request a job VNI (to be used for communication between job steps in a job). It also can be used to override the default network resources allocated for the job step. Multiple values may be specified in a comma-separated list.

The resources that may be requested are:

This option applies to job and step allocations.

--nice[=adjustment]

Run the job with an adjusted scheduling priority within Slurm. With no adjustment value the scheduling priority is decreased by 100. A negative nice value increases the priority, otherwise decreases it. The adjustment range is +/- 2147483645. Only privileged users can specify a negative adjustment.

-Z, --no-allocate

Run the specified tasks on a set of nodes without creating a Slurm "job" in the Slurm queue structure, bypassing the normal resource allocation step. The list of nodes must be specified with the -w, --nodelist option. This is a privileged option only available for the users "SlurmUser" and "root". This option applies to job allocations. If user namespaces are active, then the mapping of users in the namespace must match the same namespace as MUNGE. If not, then the job will be rejected by slurmd.

-k, --no-kill[=off]

Do not automatically terminate a job if one of the nodes it has been allocated fails. This option applies to job and step allocations. The job will assume all responsibilities for fault-tolerance. Tasks launched using this option will not be considered terminated (e.g. -K, --kill-on-bad-exit and -W, --wait options will have no effect upon the job step). The active job step (MPI job) will likely suffer a fatal error, but subsequent job steps may be run if this option is specified.

Specify an optional argument of "off" disable the effect of the SLURM_NO_KILL environment variable.

The default action is to terminate the job upon node failure.

-F, --nodefile=<node_file>

Much like --nodelist, but the list is contained in a file of name node file. The node names of the list may also span multiple lines in the file. Duplicate node names in the file will be ignored. The order of the node names in the list is not important; the node names will be sorted by Slurm.

-w, --nodelist={<node_name_list>|<filename>}

Request a specific list of hosts. The job will contain all of these hosts and possibly additional hosts as needed to satisfy resource requirements. The list may be specified as a comma-separated list of hosts, a range of hosts (host[1-5,7,...] for example), or a filename. The host list will be assumed to be a filename if it contains a "/" character. If you specify a minimum node or processor count larger than can be satisfied by the supplied host list, additional resources will be allocated on other nodes as needed. Rather than repeating a host name multiple times, an asterisk and a repetition count may be appended to a host name. For example "host1,host1" and "host1*2" are equivalent. If the number of tasks is given and a list of requested nodes is also given, the number of nodes used from that list will be reduced to match that of the number of tasks if the number of nodes in the list is greater than the number of tasks. This option applies to job and step allocations.

-N, --nodes=<minnodes>[-maxnodes]|<size_string>

Request that a minimum of minnodes nodes be allocated to this job. A maximum node count may also be specified with maxnodes. If only one number is specified, this is used as both the minimum and maximum node count. Node count can be also specified as size_string. The size_string specification identifies what nodes values should be used. Multiple values may be specified using a comma separated list or with a step function by suffix containing a colon and number values with a "-" separator. For example, "--nodes=1-15:4" is equivalent to "--nodes=1,5,9,13". The partition's node limits supersede those of the job. If a job's node limits are outside of the range permitted for its associated partition, the job will be left in a PENDING state. This permits possible execution at a later time, when the partition limit is changed. If a job node limit exceeds the number of nodes configured in the partition, the job will be rejected. Note that the environment variable SLURM_JOB_NUM_NODES (and SLURM_NNODES for backwards compatibility) will be set to the count of nodes actually allocated to the job. See the ENVIRONMENT VARIABLES section for more information. If -N is not specified, the default behavior is to allocate enough nodes to satisfy the requested resources as expressed by per-job specification options, e.g. -n, -c and --gpus. The job will be allocated as many nodes as possible within the range specified and without delaying the initiation of the job. If the number of tasks is given and a number of requested nodes is also given, the number of nodes used from that request will be reduced to match that of the number of tasks if the number of nodes in the request is greater than the number of tasks. The node count specification may include a numeric value followed by a suffix of "k" (multiplies numeric value by 1,024) or "m" (multiplies numeric value by 1,048,576). This option applies to job and step allocations.

NOTE: This option cannot be used in with arbitrary distribution.

-n, --ntasks=<number>

Specify the number of tasks to run. Request that srun allocate resources for ntasks tasks. The default is one task per node, but note that the --cpus-per-task option will change this default. This option applies to job and step allocations.

--ntasks-per-core=<ntasks>

Request the maximum ntasks be invoked on each core. This option applies to job and step allocations. Meant to be used with the --ntasks option. Related to --ntasks-per-node except at the core level instead of the node level. If set to 1, it will imply --cpu-bind=cores. Otherwise, if set to a value greater than 1, it will imply --cpu-bind=threads. Automatic binding behavior can be avoided by also specifying --cpu-bind=none. Slurm may allocate more cpus than what was requested in order to respect this option.
NOTE: This option is not supported when using SelectType=select/linear. This value can not be greater than --threads-per-core.

--ntasks-per-gpu=<ntasks>

Request that there are ntasks tasks invoked for every GPU. This option can work in two ways: 1) either specify --ntasks in addition, in which case a type-less GPU specification will be automatically determined to satisfy --ntasks-per-gpu, or 2) specify the GPUs wanted (e.g. via --gpus or --gres) without specifying --ntasks, and the total task count will be automatically determined. The number of CPUs needed will be automatically increased if necessary to allow for any calculated task count. This option will implicitly set --tres-bind=gres/gpu:single:<ntasks>, but that can be overridden with an explicit --tres-bind=gres/gpu specification. This option is not compatible with a node range (i.e. -N<minnodes-maxnodes>). This option is not compatible with --gpus-per-task, --gpus-per-socket, or --ntasks-per-node. This option is not supported unless SelectType=cons_tres is configured (either directly or indirectly on Cray systems).

--ntasks-per-node=<ntasks>

Request that ntasks be invoked on each node. If used with the --ntasks option, the --ntasks option will take precedence and the --ntasks-per-node will be treated as a maximum count of tasks per node. Meant to be used with the --nodes option. This is related to --cpus-per-task=ncpus, but does not require knowledge of the actual number of cpus on each node. In some cases, it is more convenient to be able to request that no more than a specific number of tasks be invoked on each node. Examples of this include submitting a hybrid MPI/OpenMP app where only one MPI "task/rank" should be assigned to each node while allowing the OpenMP portion to utilize all of the parallelism present in the node, or submitting a single setup/cleanup/monitoring job to each node of a pre-existing allocation as one step in a larger job script. This option applies to job allocations.

--ntasks-per-socket=<ntasks>

Request the maximum ntasks be invoked on each socket. This option applies to the job allocation, but not to step allocations. Meant to be used with the --ntasks option. Related to --ntasks-per-node except at the socket level instead of the node level. Masks will automatically be generated to bind the tasks to specific sockets unless --cpu-bind=none is specified. NOTE: This option is not supported when using SelectType=select/linear.

--open-mode={append|truncate}

Open the output and error files using append or truncate mode as specified. For heterogeneous job steps the default value is "append". Otherwise the default value is specified by the system configuration parameter JobFileAppend. This option applies to job and step allocations.

See EXAMPLE below.

-o, --output=<filename_pattern>

Specify the "filename pattern" for stdout redirection. By default in interactive mode, srun collects stdout from all tasks and sends this output via TCP/IP to the attached terminal. With --output stdout may be redirected to a file, to one file per task, or to /dev/null. See section IO Redirection below for the various forms of filename pattern. If the specified file already exists, it will be overwritten.

If --error is not also specified on the command line, both stdout and stderr will directed to the file specified by --output. This option applies to job and step allocations.

-O, --overcommit

Overcommit resources. This option applies to job and step allocations.

When applied to a job allocation (not including jobs requesting exclusive access to the nodes) the resources are allocated as if only one task per node is requested. This means that the requested number of cpus per task (-c, --cpus-per-task) are allocated per node rather than being multiplied by the number of tasks. Options used to specify the number of tasks per node, socket, core, etc. are ignored.

When applied to job step allocations (the srun command when executed within an existing job allocation), this option can be used to launch more than one task per CPU. Normally, srun will not allocate more than one process per CPU. By specifying --overcommit you are explicitly allowing more than one process per CPU. However no more than MAX_TASKS_PER_NODE tasks are permitted to execute per node. NOTE: MAX_TASKS_PER_NODE is defined in the file slurm.h and is not a variable, it is set at Slurm build time.

--overlap

Specifying --overlap allows steps to share all resources (CPUs, memory, and GRES) with all other steps. A step using this option will overlap all other steps, even those that did not specify --overlap.

By default steps do not share resources with other parallel steps. This option applies to step allocations.

-s, --oversubscribe

The job allocation can over-subscribe resources with other running jobs. The resources to be over-subscribed can be nodes, sockets, cores, and/or hyperthreads depending upon configuration. The default over-subscribe behavior depends on system configuration and the partition's OverSubscribe option takes precedence over the job's option. This option may result in the allocation being granted sooner than if the --oversubscribe option was not set and allow higher system utilization, but application performance will likely suffer due to competition for resources. This option applies to job allocations.

NOTE: This option is mutually exclusive with --exclusive.

-p, --partition=<partition_names>

Request a specific partition for the resource allocation. If not specified, the default behavior is to allow the slurm controller to select the default partition as designated by the system administrator. If the job can use more than one partition, specify their names in a comma separate list and the one offering earliest initiation will be used with no regard given to the partition name ordering (although higher priority partitions will be considered first). When the job is initiated, the name of the partition used will be placed first in the job record partition string. This option applies to job allocations.

--prefer=<list>

Nodes can have features assigned to them by the Slurm administrator. Users can specify which of these features are desired but not required by their job using the prefer option. This option operates independently from --constraint and will override whatever is set there if possible. When scheduling, the features in --prefer are tried first. If a node set isn't available with those features then --constraint is attempted. See --constraint for more information, this option behaves the same way.

-E, --preserve-env

Pass the current values of environment variables SLURM_JOB_NUM_NODES and SLURM_NTASKS through to the executable, rather than computing them from command line parameters. This option applies to job allocations.

--priority=<value>

Request a specific job priority. May be subject to configuration specific constraints. value should either be a numeric value or "TOP" (for highest possible value). Only Slurm operators and administrators can set the priority of a job. This option applies to job allocations only.

--profile={all|none|<type>[,<type>...]}

Enables detailed data collection by the acct_gather_profile plugin. Detailed data are typically time-series that are stored in an HDF5 file for the job or an InfluxDB database depending on the configured plugin. This option applies to job and step allocations.

Valid type values are:

--prolog=<executable>

srun will run executable just before launching the job step. The command line arguments for executable will be the command and arguments of the job step. If executable is "none", then no srun prolog will be run. This parameter overrides the SrunProlog parameter in slurm.conf. This parameter is completely independent from the Prolog parameter in slurm.conf. This option applies to job allocations.

--propagate[=rlimit[,rlimit...]]

Allows users to specify which of the modifiable (soft) resource limits to propagate to the compute nodes and apply to their jobs. If no rlimit is specified, then all resource limits will be propagated. The following rlimit names are supported by Slurm (although some options may not be supported on some systems):

--pty, --pty=<File Descriptor>

Execute task zero with pseudo terminal mode or using pseudo terminal specified by <File Descriptor>. Implicitly sets --unbuffered. Implicitly sets --error and --output to /dev/null for all tasks except task zero, which may cause those tasks to exit immediately (e.g. shells will typically exit immediately in that situation). This option applies to step allocations.

-q, --qos=<qos>

Request a quality of service for the job. QOS values can be defined for each user/cluster/account association in the Slurm database. Users will be limited to their association's defined set of qos's when the Slurm configuration parameter, AccountingStorageEnforce, includes "qos" in its definition. This option applies to job allocations.

-Q, --quiet

Suppress informational messages from srun. Errors will still be displayed. This option applies to job and step allocations.

--quit-on-interrupt

Quit immediately on single SIGINT (Ctrl-C). Use of this option disables the status feature normally available when srun receives a single Ctrl-C and causes srun to instead immediately terminate the running job. This option applies to step allocations.

--reboot

Force the allocated nodes to reboot before starting the job. This is only supported with some system configurations and will otherwise be silently ignored. Only root, SlurmUser or admins can reboot nodes. This option applies to job allocations.

-r, --relative=<n>

Run a job step relative to node n of the current allocation. This option may be used to spread several job steps out among the nodes of the current job. If -r is used, the current job step will begin at node n of the allocated nodelist, where the first node is considered node 0. The -r option is not permitted with -w or -x option and will result in a fatal error when not running within a prior allocation (i.e. when SLURM_JOB_ID is not set). The default for n is 0. If the value of --nodes exceeds the number of nodes identified with the --relative option, a warning message will be printed and the --relative option will take precedence. This option applies to step allocations.

--reservation=<reservation_names>

Allocate resources for the job from the named reservation. If the job can use more than one reservation, specify their names in a comma separate list and the one offering earliest initiation. Each reservation will be considered in the order it was requested. All reservations will be listed in scontrol/squeue through the life of the job. In accounting the first reservation will be seen and after the job starts the reservation used will replace it.

--resv-ports[=count]

Reserve communication ports for this job. Users can specify the number of port they want to reserve. The parameter MpiParams=ports=12000-12999 must be specified in slurm.conf. If the number of reserved ports is zero then no ports are reserved. Used for native Cray's PMI only. This option applies to job and step allocations.

--segment=<segment_size>

When a block topology is used, this defines the size of the segments that will be used to create the job allocation. No requirement would be placed on all segments for a job needing to be placed within the same higher-level block.

NOTE: The segment size must always be evenly divisible by the requested node count.

NOTE: The segment size must be less than or equal to the planning base block size. E.g., for a system with 30 nodes as the planning base block size, "--segment 40" would be invalid

--send-libs[=yes|no]

If set to yes (or no argument), autodetect and broadcast the executable's shared object dependencies to allocated compute nodes. The files are placed in a directory alongside the executable. The LD_LIBRARY_PATH is automatically updated to include this cache directory as well. This overrides the default behavior configured in slurm.conf SbcastParameters send_libs. This option only works in conjunction with --bcast. See also --bcast-exclude.

--signal=[R:]<sig_num>[@sig_time]

When a job is within sig_time seconds of its end time, send it the signal sig_num. Due to the resolution of event handling by Slurm, the signal may be sent up to 60 seconds earlier than specified. sig_num may either be a signal number or name (e.g. "10" or "USR1"). sig_time must have an integer value between 0 and 65535. By default, no signal is sent before the job's end time. If a sig_num is specified without any sig_time, the default time will be 60 seconds. This option applies to job allocations. Use the "R:" option to allow this job to overlap with a reservation with MaxStartDelay set. To have the signal sent at preemption time see the send_user_signal PreemptParameter.

--slurmd-debug=<level>

Specify a debug level for this step. The level may be specified either as an integer value between 2 [error] and 6 [debug2], or as one of the SlurmdDebug tags.

The slurmd debug information is copied onto the stderr of the job. By default only errors are displayed. This option applies to job and step allocations.

--sockets-per-node=<sockets>

Restrict node selection to nodes with at least the specified number of sockets. See additional information under -B option above when task/affinity plugin is enabled. This option applies to job allocations.
NOTE: This option may implicitly impact the number of tasks if -n was not specified.

--spread-job

Spread the job allocation over as many nodes as possible and attempt to evenly distribute tasks across the allocated nodes. This option disables the topology/tree plugin. This option applies to job allocations.

--stepmgr

Enable slurmstepd step management per-job if it isn't enabled system wide. This enables job steps to be managed by a single extern slurmstepd associated with the job to manage steps. This is beneficial for jobs that submit many steps inside their allocations. PrologFlags=contain must be set. This option applies to job allocations.

--switches=<count>[@max-time]

When a tree topology is used, this defines the maximum count of leaf switches desired for the job allocation and optionally the maximum time to wait for that number of switches. If Slurm finds an allocation containing more switches than the count specified, the job remains pending until it either finds an allocation with desired switch count or the time limit expires. It there is no switch count limit, there is no delay in starting the job. Acceptable time formats include "minutes", "minutes:seconds", "hours:minutes:seconds", "days-hours", "days-hours:minutes" and "days-hours:minutes:seconds". The job's maximum time delay may be limited by the system administrator using the SchedulerParameters configuration parameter with the max_switch_wait parameter option. On a dragonfly network the only switch count supported is 1 since communication performance will be highest when a job is allocate resources on one leaf switch or more than 2 leaf switches. The default max-time is the max_switch_wait SchedulerParameters. This option applies to job allocations.

--task-epilog=<executable>

The slurmstepd daemon will run executable just after each task terminates. This will be executed before any TaskEpilog parameter in slurm.conf is executed. This is meant to be a very short-lived program. If it fails to terminate within a few seconds, it will be killed along with any descendant processes. This option applies to step allocations.

--task-prolog=<executable>

The slurmstepd daemon will run executable just before launching each task. This will be executed after any TaskProlog parameter in slurm.conf is executed. Besides the normal environment variables, this has SLURM_TASK_PID available to identify the process ID of the task being started. Standard output from this program of the form "export NAME=value" will be used to set environment variables for the task being spawned. This option applies to step allocations.

--test-only

Returns an estimate of when a job would be scheduled to run given the current job queue and all the other srun arguments specifying the job. This limits srun's behavior to just return information; no job is actually submitted. The program will be executed directly by the slurmd daemon. This option applies to job allocations.

--thread-spec=<num>

Count of specialized threads per node reserved by the job for system operations and not used by the application. The application will not use these threads, but will be charged for their allocation. This option can not be used with the --core-spec option. This option applies to job allocations.

NOTE: Explicitly setting a job's specialized thread value implicitly sets its --exclusive option, reserving entire nodes for the job.

-T, --threads=<nthreads>

Allows limiting the number of concurrent threads used to send the job request from the srun process to the slurmd processes on the allocated nodes. Default is to use one thread per allocated node up to a maximum of 60 concurrent threads. Specifying this option limits the number of concurrent threads to nthreads (less than or equal to 60). This should only be used to set a low thread count for testing on very small memory computers.

--threads-per-core=<threads>

Restrict node selection to nodes with at least the specified number of threads per core. In task layout, use the specified maximum number of threads per core. Implies --cpu-bind=threads unless overridden by command line or environment options. NOTE: "Threads" refers to the number of processing units on each core rather than the number of application tasks to be launched per core. See additional information under -B option above when task/affinity plugin is enabled. This option applies to job and step allocations.
NOTE: This option may implicitly impact the number of tasks if -n was not specified.

-t, --time=<time>

Set a limit on the total run time of the job allocation. If the requested time limit exceeds the partition's time limit, the job will be left in a PENDING state (possibly indefinitely). The default time limit is the partition's default time limit. When the time limit is reached, each task in each job step is sent SIGTERM followed by SIGKILL. The interval between signals is specified by the Slurm configuration parameter KillWait. The OverTimeLimit configuration parameter may permit the job to run longer than scheduled. Time resolution is one minute and second values are rounded up to the next minute.

A time limit of zero requests that no time limit be imposed. Acceptable time formats include "minutes", "minutes:seconds", "hours:minutes:seconds", "days-hours", "days-hours:minutes" and "days-hours:minutes:seconds". This option applies to job and step allocations.

--time-min=<time>

Set a minimum time limit on the job allocation. If specified, the job may have its --time limit lowered to a value no lower than --time-min if doing so permits the job to begin execution earlier than otherwise possible. The job's time limit will not be changed after the job is allocated resources. This is performed by a backfill scheduling algorithm to allocate resources otherwise reserved for higher priority jobs. Acceptable time formats include "minutes", "minutes:seconds", "hours:minutes:seconds", "days-hours", "days-hours:minutes" and "days-hours:minutes:seconds". This option applies to job allocations.

--tmp=<size>[units]

Specify a minimum amount of temporary disk space per node. Default units are megabytes. Different units can be specified using the suffix [K|M|G|T]. This option applies to job allocations.

--treewidth=<size>

Specify the width of the fanout. Default is the TreeWidth specified in the slurm.conf. The value may not exceed 65533. A value of "off" disables the fanout.

--tres-bind=<tres>:[verbose,]<type>[+<tres>:

[verbose,]<type>...] Specify a list of tres with their task binding options. Currently gres are the only supported tres for this options. Specify gres as "gres/<gres_name>" (e.g. gres/gpu)

Example: --tres-bind=gres/gpu:verbose,map:0,1,2,3+gres/nic:closest

By default, most tres are not bound to individual tasks

Supported binding type options for gres:

--tres-per-task=<list>

Specifies a comma-delimited list of trackable resources required for the job on each task to be spawned in the job's resource allocation. The format for each entry in the list is "trestype[/tresname]=count". The trestype is the type of trackable resource requested (e.g. cpu, gres, license, etc). The tresname is the name of the trackable resource, as can be seen with sacctmgr show tres. This is required when it exists for tres types such as gres, license, etc. (e.g. gpu, gpu:a100). In order to request a license with this option, the license(s) must be defined in the AccountingStorageTRES parameter of slurm.conf. The count is the number of those resources.
The count can have a suffix of
"k" or "K" (multiple of 1024),
"m" or "M" (multiple of 1024 x 1024),
"g" or "G" (multiple of 1024 x 1024 x 1024),
"t" or "T" (multiple of 1024 x 1024 x 1024 x 1024),
"p" or "P" (multiple of 1024 x 1024 x 1024 x 1024 x 1024).
Examples:

--tres-per-task=cpu=4
--tres-per-task=cpu=8,license/ansys=1
--tres-per-task=gres/gpu=1
--tres-per-task=gres/gpu:a100=2

The specified resources will be allocated to the job on each node. The available trackable resources are configurable by the system administrator.
NOTE: This option with gres/gpu or gres/shard will implicitly set --tres-bind=per_task:(gpu or shard)<tres_per_task>; this can be overridden with an explicit --tres-bind specification.
NOTE: Invalid TRES for --tres-per-task include bb,billing,energy,fs,mem,node,pages,vmem.

-u, --unbuffered

By default, the connection between slurmstepd and the user-launched application is over a pipe. The stdio output written by the application is buffered by the glibc until it is flushed or the output is set as unbuffered. See setbuf(3). If this option is specified the tasks are executed with a pseudo terminal so that the application output is unbuffered. This option applies to step allocations.

--usage

Display brief help message and exit.

--use-min-nodes

If a range of node counts is given, prefer the smaller count.

-v, --verbose

Increase the verbosity of srun's informational messages. Multiple errors will be displayed. This option applies to job and step allocations.

-V, --version

Display version information and exit.

-W, --wait=<seconds>

Specify how long to wait after the first task terminates before terminating all remaining tasks. A value of 0 indicates an unlimited wait (a warning will be issued after 60 seconds). The default value is set by the WaitTime parameter in the slurm configuration file (see slurm.conf(5)). This option can be useful to ensure that a job is terminated in a timely fashion in the event that one or more tasks terminate prematurely. Note: The -K, --kill-on-bad-exit option takes precedence over -W, --wait to terminate the job immediately if a task exits with a non-zero exit code. This option applies to job allocations.

--wckey=<wckey>

Specify wckey to be used with job. If TrackWCKey=no (default) in the slurm.conf this value is ignored. This option applies to job allocations.

--x11[={all|first|last}]

Sets up X11 forwarding on "all", "first" or "last" node(s) of the allocation. This option is only enabled if Slurm was compiled with X11 support and PrologFlags=x11 is defined in the slurm.conf. Default is "all".

srun will submit the job request to the slurm job controller, then initiate all processes on the remote nodes. If the request cannot be met immediately, srun will block until the resources are free to run the job. If the -I (--immediate) option is specified srun will terminate if resources are not immediately available.

When initiating remote processes srun will propagate the current working directory, unless --chdir=<path> is specified, in which case path will become the working directory for the remote processes.

The -n, -c, and -N options control how CPUs and nodes will be allocated to the job. When specifying only the number of processes to run with -n, a default of one CPU per process is allocated. By specifying the number of CPUs required per task (-c), more than one CPU may be allocated per process. If the number of nodes is specified with -N, srun will attempt to allocate at least the number of nodes specified.

Combinations of the above three options may be used to change how processes are distributed across nodes and cpus. For instance, by specifying both the number of processes and number of nodes on which to run, the number of processes per node is implied. However, if the number of CPUs per process is more important then number of processes (-n) and the number of CPUs per process (-c) should be specified.

srun will refuse to allocate more than one process per CPU unless --overcommit (-O) is also specified.

srun will attempt to meet the above specifications "at a minimum." That is, if 16 nodes are requested for 32 processes, and some nodes do not have 2 CPUs, the allocation of nodes will be increased in order to meet the demand for CPUs. In other words, a minimum of 16 nodes are being requested. However, if 16 nodes are requested for 15 processes, srun will consider this an error, as 15 processes cannot run across 16 nodes.

IO Redirection

By default, stdout and stderr will be redirected from all tasks to the stdout and stderr of srun, and stdin will be redirected from the standard input of srun to all remote tasks. If stdin is only to be read by a subset of the spawned tasks, specifying a file to read from rather than forwarding stdin from the srun command may be preferable as it avoids moving and storing data that will never be read.

For OS X, the poll() function does not support stdin, so input from a terminal is not possible.

This behavior may be changed with the --output, --error, and --input (-o, -e, -i) options. Note that --error won't redirect the stderr of srun itself, only the stderr from the tasks. Valid format specifications for these options are

all

stdout stderr is redirected from all tasks to srun. stdin is broadcast to all remote tasks. (This is the default behavior)

none

stdout and stderr is not received from any task. stdin is not sent to any task (stdin is closed).

taskid

stdout and/or stderr are redirected from only the task with relative id equal to taskid, where 0 <= taskid <= ntasks, where ntasks is the total number of tasks in the current job step. stdin is redirected from the stdin of srun to this same task. This file will be written on the node executing the task.

filename

srun will redirect stdout and/or stderr to the named file from all tasks. stdin will be redirected from the named file and broadcast to all tasks in the job. filename refers to a path on the host that runs srun. Depending on the cluster's file system layout, this may result in the output appearing in different places depending on whether the job is run in batch mode.

filename pattern

srun allows for a filename pattern to be used to generate the named IO file described above. The following list of format specifiers may be used in the format string to generate a filename that will be unique to a given jobid, stepid, node, or task. In each case, the appropriate number of files are opened and associated with the corresponding tasks. Note that any format string containing %t, %n, and/or %N will be written on the node executing the task rather than the node where srun executes, these format specifiers are not supported on a BGQ system.

PERFORMANCE¶

Executing srun sends a remote procedure call to slurmctld. If enough calls from srun or other Slurm client commands that send remote procedure calls to the slurmctld daemon come in at once, it can result in a degradation of performance of the slurmctld daemon, possibly resulting in a denial of service.

Do not run srun or other Slurm client commands that send remote procedure calls to slurmctld from loops in shell scripts or other programs. Ensure that programs limit calls to srun to the minimum necessary for the information you are trying to gather.

INPUT ENVIRONMENT VARIABLES¶

Upon startup, srun will read and handle the options set in the following environment variables. The majority of these variables are set the same way the options are set, as defined above. For flag options that are defined to expect no argument, the option can be enabled by setting the environment variable without a value (empty or NULL string), the string 'yes', or a non-zero number. Any other value for the environment variable will result in the option not being set. There are a couple exceptions to these rules that are noted below.
NOTE: Command line options always override environment variable settings.

PMI_FANOUT

This is used exclusively with PMI (MPICH2 and MVAPICH2) and controls the fanout of data communications. The srun command sends messages to application programs (via the PMI library) and those applications may be called upon to forward that data to up to this number of additional tasks. Higher values offload work from the srun command to the applications and likely increase the vulnerability to failures. The default value is 32.

PMI_FANOUT_OFF_HOST

This is used exclusively with PMI (MPICH2 and MVAPICH2) and controls the fanout of data communications. The srun command sends messages to application programs (via the PMI library) and those applications may be called upon to forward that data to additional tasks. By default, srun sends one message per host and one task on that host forwards the data to other tasks on that host up to PMI_FANOUT. If PMI_FANOUT_OFF_HOST is defined, the user task may be required to forward the data to tasks on other hosts. Setting PMI_FANOUT_OFF_HOST may increase performance. Since more work is performed by the PMI library loaded by the user application, failures also can be more common and more difficult to diagnose. Should be disabled/enabled by setting to 0 or 1.

PMI_TIME

This is used exclusively with PMI (MPICH2 and MVAPICH2) and controls how much the communications from the tasks to the srun are spread out in time in order to avoid overwhelming the srun command with work. The default value is 500 (microseconds) per task. On relatively slow processors or systems with very large processor counts (and large PMI data sets), higher values may be required.

SLURM_ACCOUNT

Same as -A, --account

SLURM_ACCTG_FREQ

Same as --acctg-freq

SLURM_BCAST

Same as --bcast

SLURM_BCAST_EXCLUDE

Same as --bcast-exclude

SLURM_BURST_BUFFER

Same as --bb

SLURM_CLUSTERS

Same as -M, --clusters

SLURM_COMPRESS

Same as --compress

SLURM_CONF

The location of the Slurm configuration file.

SLURM_CONSTRAINT

Same as -C, --constraint

SLURM_CORE_SPEC

Same as --core-spec

SLURM_CPU_BIND

Same as --cpu-bind

SLURM_CPU_FREQ_REQ

Same as --cpu-freq.

SLURM_CPUS_PER_GPU

Same as --cpus-per-gpu

SLURM_CPUS_PER_TASK

Same as -c, --cpus-per-task or --tres-per-task=cpu=#

SLURM_DEBUG

Same as -v, --verbose, when set to 1, when set to 2 gives -vv, etc.

SLURM_DEBUG_FLAGS

Specify debug flags for srun to use. See DebugFlags in the slurm.conf(5) man page for a full list of flags. The environment variable takes precedence over the setting in the slurm.conf.

SLURM_DELAY_BOOT

Same as --delay-boot

SLURM_DEPENDENCY

Same as -d, --dependency=<jobid>

SLURM_DISABLE_STATUS

Same as -X, --disable-status

SLURM_DIST_PLANESIZE

Plane distribution size. Only used if --distribution=plane, without =<size>, is set.

SLURM_DISTRIBUTION

Same as -m, --distribution

SLURM_EPILOG

Same as --epilog

SLURM_EXACT

Same as --exact

SLURM_EXCLUSIVE

Same as --exclusive

SLURM_EXIT_ERROR

Specifies the exit code generated when a Slurm error occurs (e.g. invalid options). This can be used by a script to distinguish application exit codes from various Slurm error conditions. Also see SLURM_EXIT_IMMEDIATE.

SLURM_EXIT_IMMEDIATE

Specifies the exit code generated when the --immediate option is used and resources are not currently available. This can be used by a script to distinguish application exit codes from various Slurm error conditions. Also see SLURM_EXIT_ERROR.

SLURM_EXPORT_ENV

Same as --export

SLURM_GPU_BIND

Same as --gpu-bind

SLURM_GPU_FREQ

Same as --gpu-freq

SLURM_GPUS

Same as -G, --gpus

SLURM_GPUS_PER_NODE

Same as --gpus-per-node

SLURM_GPUS_PER_TASK

Same as --gpus-per-task

SLURM_GRES

Same as --gres. Also see SLURM_STEP_GRES

SLURM_GRES_FLAGS

Same as --gres-flags

SLURM_HINT

Same as --hint

SLURM_IMMEDIATE

Same as -I, --immediate

SLURM_JOB_ID

Same as --jobid

SLURM_JOB_NAME

Same as -J, --job-name except within an existing allocation, in which case it is ignored to avoid using the batch job's name as the name of each job step.

SLURM_JOB_NUM_NODES

Same as -N, --nodes. Total number of nodes in the job's resource allocation.

SLURM_KILL_BAD_EXIT

Same as -K, --kill-on-bad-exit. Must be set to 0 or 1 to disable or enable the option.

SLURM_LABELIO

Same as -l, --label

SLURM_MEM_BIND

Same as --mem-bind

SLURM_MEM_PER_CPU

Same as --mem-per-cpu

SLURM_MEM_PER_GPU

Same as --mem-per-gpu

SLURM_MEM_PER_NODE

Same as --mem

SLURM_MPI_TYPE

Same as --mpi

SLURM_NETWORK

Same as --network

SLURM_NNODES

Same as -N, --nodes. Total number of nodes in the job's resource allocation. See SLURM_JOB_NUM_NODES. Included for backwards compatibility.

SLURM_NO_KILL

Same as -k, --no-kill

SLURM_NPROCS

Same as -n, --ntasks. See SLURM_NTASKS. Included for backwards compatibility.

SLURM_NTASKS

Same as -n, --ntasks

SLURM_NTASKS_PER_CORE

Same as --ntasks-per-core

SLURM_NTASKS_PER_GPU

Same as --ntasks-per-gpu

SLURM_NTASKS_PER_NODE

Same as --ntasks-per-node

SLURM_NTASKS_PER_SOCKET

Same as --ntasks-per-socket

SLURM_OPEN_MODE

Same as --open-mode

SLURM_OVERCOMMIT

Same as -O, --overcommit

SLURM_OVERLAP

Same as --overlap

SLURM_PARTITION

Same as -p, --partition

SLURM_PMI_KVS_NO_DUP_KEYS

If set, then PMI key-pairs will contain no duplicate keys. MPI can use this variable to inform the PMI library that it will not use duplicate keys so PMI can skip the check for duplicate keys. This is the case for MPICH2 and reduces overhead in testing for duplicates for improved performance

SLURM_POWER

Same as --power

SLURM_PROFILE

Same as --profile

SLURM_PROLOG

Same as --prolog

SLURM_QOS

Same as --qos

SLURM_REMOTE_CWD

Same as -D, --chdir=

SLURM_REQ_SWITCH

When a tree topology is used, this defines the maximum count of switches desired for the job allocation and optionally the maximum time to wait for that number of switches. See --switches

SLURM_RESERVATION

Same as --reservation

SLURM_RESV_PORTS

Same as --resv-ports

SLURM_SEND_LIBS

Same as --send-libs

SLURM_SIGNAL

Same as --signal

SLURM_SPREAD_JOB

Same as --spread-job

SLURM_SRUN_REDUCE_TASK_EXIT_MSG

if set and non-zero, successive task exit messages with the same exit code will be printed only once.

SRUN_ERROR

Same as -e, --error

SRUN_INPUT

Same as -i, --input

SRUN_OUTPUT

Same as -o, --output

SLURM_STEP_GRES

Same as --gres (only applies to job steps, not to job allocations). Also see SLURM_GRES

SLURM_STEP_KILLED_MSG_NODE_ID=ID

If set, only the specified node will log when the job or step are killed by a signal.

SLURM_TASK_EPILOG

Same as --task-epilog

SLURM_TASK_PROLOG

Same as --task-prolog

SLURM_TEST_EXEC

If defined, srun will verify existence of the executable program along with user execute permission on the node where srun was called before attempting to launch it on nodes in the step.

SLURM_THREAD_SPEC

Same as --thread-spec

SLURM_THREADS

Same as -T, --threads

SLURM_THREADS_PER_CORE

Same as --threads-per-core

SLURM_TIMELIMIT

Same as -t, --time

SLURM_TRES_BIND

Same as --tres-bind If --gpu-bind is specified, it is also set in SLURM_TRES_BIND as if it were specified in --tres-bind.

SLURM_TRES_PER_TASK

Set to the value of --tres-per-task. If --cpus-per-task or --gpus-per-task is specified, it is also set in SLURM_TRES_PER_TASK as if it were specified in --tres-per-task.

SLURM_UMASK

If defined, Slurm will use the defined umask to set permissions when creating the output/error files for the job.

SLURM_UNBUFFEREDIO

Same as -u, --unbuffered

SLURM_USE_MIN_NODES

Same as --use-min-nodes

SLURM_WAIT

Same as -W, --wait

SLURM_WAIT4SWITCH

Max time waiting for requested switches. See --switches

SLURM_WCKEY

Same as -W, --wckey

SLURM_WORKING_DIR

-D, --chdir

SLURMD_DEBUG

Same as --slurmd-debug.

SRUN_CONTAINER

Same as --container.

SRUN_CONTAINER_ID

Same as --container-id.

SRUN_EXPORT_ENV

Same as --export, and will override any setting for SLURM_EXPORT_ENV.

OUTPUT ENVIRONMENT VARIABLES¶

srun will set some environment variables in the environment of the executing tasks on the remote compute nodes. These environment variables are:

SLURM_*_HET_GROUP_#

For a heterogeneous job allocation, the environment variables are set separately for each component.

SLURM_CLUSTER_NAME

Name of the cluster on which the job is executing.

SLURM_CPU_BIND_LIST

--cpu-bind map or mask list (list of Slurm CPU IDs or masks for this node, CPU_ID = Board_ID x threads_per_board + Socket_ID x threads_per_socket + Core_ID x threads_per_core + Thread_ID).

SLURM_CPU_BIND_TYPE

--cpu-bind type (none,rank,map_cpu:,mask_cpu:).

SLURM_CPU_BIND_VERBOSE

--cpu-bind verbosity (quiet,verbose).

SLURM_CPU_FREQ_REQ

Contains the value requested for cpu frequency on the srun command as a numerical frequency in kilohertz, or a coded value for a request of low, medium,highm1 or high for the frequency. See the description of the --cpu-freq option or the SLURM_CPU_FREQ_REQ input environment variable.

SLURM_CPUS_ON_NODE

Number of CPUs available to the step on this node. NOTE: The select/linear plugin allocates entire nodes to jobs, so the value indicates the total count of CPUs on the node. For the cons/tres plugin, this number indicates the number of CPUs on this node allocated to the step.

SLURM_CPUS_PER_TASK

Number of cpus requested per task. Only set if either the --cpus-per-task option or the --tres-per-task=cpu=# option is specified.

SLURM_DISTRIBUTION

Distribution type for the allocated jobs. Set the distribution with -m, --distribution.

SLURM_GPUS_ON_NODE

Number of GPUs available to the step on this node.

SLURM_GTIDS

Global task IDs running on this node. Zero origin and comma separated. It is read internally by pmi if Slurm was built with pmi support. Leaving the variable set may cause problems when using external packages from within the job (Abaqus and Ansys have been known to have problems when it is set - consult the appropriate documentation for 3rd party software).

SLURM_HET_SIZE

Set to count of components in heterogeneous job.

SLURM_JOB_ACCOUNT

Account name associated of the job allocation.

SLURM_JOB_CPUS_PER_NODE

Count of CPUs available to the job on the nodes in the allocation, using the format CPU_count[(xnumber_of_nodes)][,CPU_count [(xnumber_of_nodes)] ...]. For example: SLURM_JOB_CPUS_PER_NODE='72(x2),36' indicates that on the first and second nodes (as listed by SLURM_JOB_NODELIST) the allocation has 72 CPUs, while the third node has 36 CPUs. NOTE: The select/linear plugin allocates entire nodes to jobs, so the value indicates the total count of CPUs on allocated nodes. The select/cons_tres plugin allocates individual CPUs to jobs, so this number indicates the number of CPUs allocated to the job.

SLURM_JOB_DEPENDENCY

Set to value of the --dependency option.

SLURM_JOB_END_TIME

The UNIX timestamp for a job's projected end time.

SLURM_JOB_GPUS

The global GPU IDs of the GPUs allocated to this job. The GPU IDs are not relative to any device cgroup, even if devices are constrained with task/cgroup. Only set in batch and interactive jobs.

SLURM_JOB_ID

Job id of the executing job.

SLURM_JOB_LICENSES

Name and count of any license(s) requested.

SLURM_JOB_NAME

Set to the value of the --job-name option or the command name when srun is used to create a new job allocation. Not set when srun is used only to create a job step (i.e. within an existing job allocation).

SLURM_JOB_NODELIST

List of nodes allocated to the job.

SLURM_JOB_NODES

Total number of nodes in the job's resource allocation.

SLURM_JOB_PARTITION

Name of the partition in which the job is running.

SLURM_JOB_QOS

Quality Of Service (QOS) of the job allocation.

SLURM_JOB_RESERVATION

Advanced reservation containing the job allocation, if any.

SLURM_JOB_START_TIME

The UNIX timestamp for a job's start time.

SLURM_JOBID

Job id of the executing job. See SLURM_JOB_ID. Included for backwards compatibility.

SLURM_LAUNCH_NODE_IPADDR

IP address of the node from which the task launch was initiated (where the srun command ran from).

SLURM_LOCALID

Node local task ID for the process within a job.

SLURM_MEM_BIND_LIST

--mem-bind map or mask list (<list of IDs or masks for this node>).

SLURM_MEM_BIND_PREFER

--mem-bind prefer (prefer).

SLURM_MEM_BIND_SORT

Sort free cache pages (run zonesort on Intel KNL nodes).

SLURM_MEM_BIND_TYPE

--mem-bind type (none,rank,map_mem:,mask_mem:).

SLURM_MEM_BIND_VERBOSE

--mem-bind verbosity (quiet,verbose).

SLURM_NODEID

The relative node ID of the current node.

SLURM_NPROCS

Total number of processes in the current job or job step. See SLURM_NTASKS. Included for backwards compatibility.

SLURM_NTASKS

Total number of processes in the current job or job step.

SLURM_OVERCOMMIT

Set to 1 if --overcommit was specified.

SLURM_PRIO_PROCESS

The scheduling priority (nice value) at the time of job submission. This value is propagated to the spawned processes.

SLURM_PROCID

The MPI rank (or relative process ID) of the current process.

SLURM_SRUN_COMM_HOST

IP address of srun communication host.

SLURM_SRUN_COMM_PORT

srun communication port.

SLURM_CONTAINER

OCI Bundle for job. Only set if --container is specified.

SLURM_CONTAINER_ID

OCI id for job. Only set if --container_id is specified.

SLURM_SHARDS_ON_NODE

Number of GPU Shards available to the step on this node.

SLURM_STEP_GPUS

The global GPU IDs of the GPUs allocated to this step (excluding batch and interactive steps). The GPU IDs are not relative to any device cgroup, even if devices are constrained with task/cgroup.

SLURM_STEP_ID

The step ID of the current job.

SLURM_STEP_LAUNCHER_PORT

Step launcher port.

SLURM_STEP_NODELIST

List of nodes allocated to the step.

SLURM_STEP_NUM_NODES

Number of nodes allocated to the step.

SLURM_STEP_NUM_TASKS

Number of processes in the job step or whole heterogeneous job step.

SLURM_STEP_TASKS_PER_NODE

Number of processes per node within the step.

SLURM_STEPID

The step ID of the current job. See SLURM_STEP_ID. Included for backwards compatibility.

SLURM_SUBMIT_DIR

The directory from which the allocation was invoked from.

SLURM_SUBMIT_HOST

The hostname of the computer from which the allocation was invoked from.

SLURM_TASK_PID

The process ID of the task being started.

SLURM_TASKS_PER_NODE

Number of tasks to be initiated on each node. Values are comma separated and in the same order as SLURM_JOB_NODELIST. If two or more consecutive nodes are to have the same task count, that count is followed by "(x#)" where "#" is the repetition count. For example, "SLURM_TASKS_PER_NODE=2(x3),1" indicates that the first three nodes will each execute two tasks and the fourth node will execute one task.

SLURM_TOPOLOGY_ADDR

This is set only if the system has the topology/tree plugin configured. The value will be set to the names network switches which may be involved in the job's communications from the system's top level switch down to the leaf switch and ending with node name. A period is used to separate each hardware component name.

SLURM_TOPOLOGY_ADDR_PATTERN

This is set only if the system has the topology/tree plugin configured. The value will be set component types listed in SLURM_TOPOLOGY_ADDR. Each component will be identified as either "switch" or "node". A period is used to separate each hardware component type.

SLURM_TRES_PER_TASK

Set to the value of --tres-per-task.

SLURM_UMASK

The umask in effect when the job was submitted.

SLURMD_NODENAME

Name of the node running the task. In the case of a parallel job executing on multiple compute nodes, the various tasks will have this environment variable set to different values on each compute node.

SRUN_DEBUG

Set to the logging level of the srun command. Default value is 3 (info level). The value is incremented or decremented based upon the --verbose and --quiet options.

SIGNALS AND ESCAPE SEQUENCES¶

Signals sent to the srun command are automatically forwarded to the tasks it is controlling with a few exceptions. The escape sequence <control-c> will report the state of all tasks associated with the srun command. If <control-c> is entered twice within one second, then the associated SIGINT signal will be sent to all tasks and a termination sequence will be entered sending SIGCONT, SIGTERM, and SIGKILL to all spawned tasks. If a third <control-c> is received, the srun program will be terminated without waiting for remote tasks to exit or their I/O to complete.

The escape sequence <control-z> is presently ignored.

MPI SUPPORT¶

MPI use depends upon the type of MPI being used. There are three fundamentally different modes of operation used by these various MPI implementations.

1. Slurm directly launches the tasks and performs initialization of communications through the PMI2 or PMIx APIs. For example: "srun -n16 a.out".

2. Slurm creates a resource allocation for the job and then mpirun launches tasks using Slurm's infrastructure (OpenMPI).

3. Slurm creates a resource allocation for the job and then mpirun launches tasks using some mechanism other than Slurm, such as SSH or RSH. These tasks are initiated outside of Slurm's monitoring or control. Slurm's epilog should be configured to purge these tasks when the job's allocation is relinquished, or the use of pam_slurm_adopt is highly recommended.

See https://slurm.schedmd.com/mpi_guide.html for more information on use of these various MPI implementations with Slurm.

MULTIPLE PROGRAM CONFIGURATION¶

Comments in the configuration file must have a "#" in column one. The configuration file contains the following fields separated by white space:

Task rank

One or more task ranks to use this configuration. Multiple values may be comma separated. Ranges may be indicated with two numbers separated with a '-' with the smaller number first (e.g. "0-4" and not "4-0"). To indicate all tasks not otherwise specified, specify a rank of '*' as the last line of the file. If an attempt is made to initiate a task for which no executable program is defined, the following error message will be produced "No executable program specified for this task".

Executable

The name of the program to execute. May be fully qualified pathname if desired.

Arguments

Program arguments. The expression "%t" will be replaced with the task's number. The expression "%o" will be replaced with the task's offset within this range (e.g. a configured task rank value of "1-5" would have offset values of "0-4"). Single quotes may be used to avoid having the enclosed values interpreted. This field is optional. Any arguments for the program entered on the command line will be added to the arguments specified in the configuration file.

For example:

$ cat silly.conf
###################################################################
# srun multiple program configuration file
#
# srun -n8 -l --multi-prog silly.conf
###################################################################
4-6       hostname
1,7       echo  task:%t
0,2-3     echo  offset:%o
$ srun -n8 -l --multi-prog silly.conf
0: offset:0
1: task:1
2: offset:1
3: offset:2
4: linux15.llnl.gov
5: linux16.llnl.gov
6: linux17.llnl.gov
7: task:7

EXAMPLES¶

Example 1:

This simple example demonstrates the execution of the command hostname in eight tasks. At least eight processors will be allocated to the job (the same as the task count) on however many nodes are required to satisfy the request. The output of each task will be proceeded with its task number. (The machine "dev" in the example below has a total of two CPUs per node)

$ srun -n8 -l hostname
0: dev0
1: dev0
2: dev1
3: dev1
4: dev2
5: dev2
6: dev3
7: dev3

Example 2:

The srun -r option is used within a job script to run two job steps on disjoint nodes in the following example. The script is run using allocate mode instead of as a batch job in this case.

$ cat test.sh
#!/bin/sh
echo $SLURM_JOB_NODELIST
srun -lN2 -r2 hostname
srun -lN2 hostname
$ salloc -N4 test.sh
dev[7-10]
0: dev9
1: dev10
0: dev7
1: dev8

Example 3:

The following script runs two job steps in parallel within an allocated set of nodes.

$ cat test.sh
#!/bin/bash
srun -lN2 -n4 -r 2 sleep 60 &
srun -lN2 -r 0 sleep 60 &
sleep 1
squeue
squeue -s
wait
$ salloc -N4 test.sh


  JOBID PARTITION     NAME     USER  ST      TIME  NODES NODELIST


  65641     batch  test.sh   grondo   R      0:01      4 dev[7-10]
STEPID     PARTITION     USER      TIME NODELIST
65641.0        batch   grondo      0:01 dev[7-8]
65641.1        batch   grondo      0:01 dev[9-10]

Example 4:

This example demonstrates how one executes a simple MPI job. We use srun to build a list of machines (nodes) to be used by mpirun in its required format. A sample command line and the script to be executed follow.

$ cat test.sh
#!/bin/sh
MACHINEFILE="nodes.$SLURM_JOB_ID"
# Generate Machinefile for mpi such that hosts are in the same
#  order as if run via srun
#
srun -l /bin/hostname | sort -n | awk '{print $2}' > $MACHINEFILE
# Run using generated Machine file:
mpirun -np $SLURM_NTASKS -machinefile $MACHINEFILE mpi-app
rm $MACHINEFILE
$ salloc -N2 -n4 test.sh

Example 5:

This simple example demonstrates the execution of different jobs on different nodes in the same srun. You can do this for any number of nodes or any number of jobs. The executables are placed on the nodes sited by the SLURM_NODEID env var. Starting at 0 and going to the number specified on the srun command line.

$ cat test.sh
case $SLURM_NODEID in


    0) echo "I am running on "


       hostname ;;


    1) hostname


       echo "is where I am running" ;;
esac
$ srun -N2 test.sh
dev0
is where I am running
I am running on
dev1

Example 6:

This example demonstrates use of multi-core options to control layout of tasks. We request that four sockets per node and two cores per socket be dedicated to the job.

$ srun -N2 -B 4-4:2-2 a.out

Example 7:

This example shows a script in which Slurm is used to provide resource management for a job by executing the various job steps as processors become available for their dedicated use.

$ cat my.script
#!/bin/bash
srun -n4 prog1 &
srun -n3 prog2 &
srun -n1 prog3 &
srun -n1 prog4 &
wait

Example 8:

This example shows how to launch an application called "server" with one task, 8 CPUs and 16 GB of memory (2 GB per CPU) plus another application called "client" with 16 tasks, 1 CPU per task (the default) and 1 GB of memory per task.

$ srun -n1 -c8 --mem-per-cpu=2gb server : -n16 --mem-per-cpu=1gb client

Example 9:

This example highlights the difference in behavior with srun's --exclusive and --overlap flags when run from inside a job allocation. The --overlap flag allows both steps to start at the same time. The --exclusive flag makes the second step wait until the first has finished.

$ salloc  -n1
salloc: Granted job allocation 9553
salloc: Waiting for resource configuration
salloc: Nodes node01 are ready for job
$ date +%T; srun -n1 --overlap -l sleep 3 &
$ srun -n1 --overlap -l date +%T &
14:36:04
[1] 144341
[2] 144342
0: 14:36:04
[2]+  Done                    srun -n1 --overlap -l date +%T
[1]+  Done                    srun -n1 --overlap -l sleep 3
$ date +%T; srun -n1 --exclusive -l sleep 3 &
$ srun -n1 --exclusive -l date +%T &
14:36:17
[1] 144429
[2] 144430
srun: Job 9553 step creation temporarily disabled, retrying (Requested nodes are busy)
srun: Step created for job 9553
0: 14:36:20
[1]-  Done                    srun -n1 --exclusive -l sleep 3
[2]+  Done                    srun -n1 --exclusive -l date +%T

Example 10:

This example demonstrates how jobs that are not evenly split among multiple nodes can run into problems of tasks not being able to start when there are enough CPUs free to run that task on a single node. This example shows a job that was allocated 2 CPUs on one node and 24 CPUs on the other node.

$ echo $SLURM_NODELIST; echo $SLURM_JOB_CPUS_PER_NODE
node[01-02]
2,24

If a task is started that occupies the CPUs on the node with fewer CPUs, then a subsequent task that should be able to start on the other node will not start because it inherits the requirement for the number of nodes from the job allocation. The job step will stay pending until the first job step completes or until it is cancelled.

$ srun -n4 --exact sleep 1800 &
[1] 151837
$ srun -n2 --exact hostname
^Csrun: Cancelled pending job step with signal 2
srun: error: Unable to create step for job 2677: Job/step already completing or completed

If the job step is started, explicitly requesting a single node, then the step is able to run.

$ srun -n2 -N1 --exact hostname
node02
node02

This behavior can be changed by adding SelectTypeParameters=CR_Pack_Nodes to your slurm.conf. The logic to pack nodes will allow job steps to start on a single node without having to explicitly request a single node.

COPYING¶

Copyright (C) 2006-2007 The Regents of the University of California. Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
Copyright (C) 2008-2010 Lawrence Livermore National Security.
Copyright (C) 2010-2022 SchedMD LLC.

This file is part of Slurm, a resource management program. For details, see <https://slurm.schedmd.com/>.

Slurm is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

Slurm is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

SEE ALSO¶

salloc(1), sattach(1), sbatch(1), sbcast(1), scancel(1), scontrol(1), squeue(1), slurm.conf(5), sched_setaffinity (2), numa (3) getrlimit (2)