NAME¶

mount.diod - mount diod file systems

SYNOPSIS¶

mount.diod [OPTIONS] host[:aname] dir [-o options]

DESCRIPTION¶

mount.diod is the mount utility for the distributed I/O daemon, which is an I/O forwarding service for Linux clusters built upon the Linux 9p file system.

mount.diod performs two main tasks: 1) connect and authenticate to the diod server, and 2) issue the mount(2) system call with appropriate mount options.

Authentication with the diod server takes place in user space. The connected (and authenticated) file descriptor is passed as a mount option to the kernel 9p file system

This command requires root to execute the mount(2) system call.

The 9p file system must support the 9P2000.L protocol variant, e.g. kernel 2.6.38 or above.

The host portion of the mount spec may optionally be supplied in hostlist format, e.g. host1,host2,host3:aname or host[1-3]:aname, in which case hosts are tried in order until a successful connection is obtained. Post-connect mount errors are immediately fatal.

If the host portion of the mount spec begins with a forward-slash (/), it refers to the path to a UNIX domain socket.

IPv6 addresses may be used for the host portion of the mount spec if they are enclosed in square brackets.

COMMAND LINE OPTIONS¶

-f, --fake-mount

Do everything except the mount system call.

-n, --no-mtab

Do not update the system mtab.

-v, --verbose

Set verbose mode.

-o, --options opt[,opt,...]

Set mount options (see below).

-p, --privport

Connect from a socket bound to a port in the range of 512-1023, available to root only. This can be used in conjunction with the privport export option.

MOUNT OPTIONS¶

For a complete list of v9fs mount options, refer to the kernel documentation at https://docs.kernel.org/filesystems/9p.html. Some common options are described below.

aname=PATH

The aname is the path of the exported file system on the server. It can be specified in the mount spec in host:aname format like NFS, or it can be specified with this option. diod will not allow an attach to an empty aname. diod has a built-in synthetic control file system that can be mounted with aname of ctl. Note that "ctl" must be explicitly exported.

uname=USERNAME

The user name to authenticate to the diod server. If neither uname nor access are specified, uname=root,access=client is assumed.

access=client

The client allows any user to access the file system and enforces access control. Each new user attaches to the server. Requires uname=root.

access=user

The same as access=client, but a weaker guarantee that the client performs access control. diod users are encouraged to use access=client. Requires uname=root.

access=UID

The client only allows UID to access the filesystem. Only the authenticated user attaches to the server.

access=any

The client allows any user to access the filesystem. Only the authenticated user attaches to the server.

posixacl

Enforce POSIX access control lists. Requires uname=root and access=client.

port=N

Connect to the diod server on the specified port. The default is the IANA-assigned 9pfs port 564.

trans=fd

Select a transport. mount.diod only supports trans=fd because of its strategy for authentication.

rfdno=N,wfdno=N

The file descriptor for reading and writing with trans=fd. If set, mount.diod assumes this file descriptor is already connected to a diod server and ignores host in the device specification, and the port=n option.

msize=N

The msize is the max 9P packet payload size. The default is 65512 (65536-24)

version=9p20000.L

Select 9P protocol version. diod only supports 9p2000.L.

cache=MODE

Specify a caching policy. Cache modes include none (default), readahead, mmap, loose, and fscache.

debug=MASK

Specifies debug level for the kernel 9p module. The debug level is a bitmask.
0x01 = display verbose error messages
0x02 = developer debug (DEBUG_CURRENT)
0x04 = display 9p trace
0x08 = display VFS trace
0x10 = display Marshalling debug
0x20 = display RPC debug
0x40 = display transport debug
0x80 = display allocation debug
0x100 = display protocol message debug
0x200 = display Fid debug
0x400 = display packet debug
0x800 = display fscache tracing debug
The debug level is global, i.e. it applies to all 9P file systems and it remains set after the file system is unmounted. The default is debug=0.

SEE ALSO¶

diod (8)