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CDEMU-DAEMON(8) System Manager's Manual CDEMU-DAEMON(8)


cdemud - The CDEmu daemon


cdemu-daemon [options]


This is CDEmu daemon, the userspace part of the cdemu suite, a free, GPL CD/DVD-ROM device emulator for linux.

It receives SCSI commands from kernel module and processes them, passing the requested data back to the kernel. Daemon implements the actual virtual device; one instance per each device registered by kernel module. It uses libMirage, an image access library that is part of the cdemu suite, for the image access (e.g. sector reading).

The daemon registers itself on D-BUS' system or session bus (depending on the options passed to it) where it exposes an interface that can be used by clients to control it.


Configuration file to load. See Configuration file section for details.
Number of devices. Specifies the number of virtual devices the daemon instance should register with kernel module and control. By default, 1 virtual device is created.
Control device. Specifies the control device path. Control device is a character device provided by kernel module; it is used for communication between kernel and userspace part of CDEmu suite. By default, /dev/vhba_ctl is used.
Audio driver. Specifies audio driver to be used by virtual devices' audio play. Since libao is used for audio playback, any valid libao driver can be specified. If default is used as a driver, then libao's default driver is used. Few examples of valid libao drivers are alsa, oss, pulse or null. For all drivers, default device is used. By default, if audio driver is not explicitly specified via this option, null is used.
Bus type. Valid options are system or session. By default, session bus is used. (Please note that the running of CDEmu daemon on system bus is considered deprecated and is discouraged for security reasons).
Log file to write logging output into. By default, use of log file is disabled and messages are written to stdout.
Default debug mask for CDEmu devices (at CDEmu daemon implementation level). Default value is 0.
Default debug mask for CDEmu devices (at libMirage implementation level). Default value is 0.
-? --help
Display the help message.


cdemu-daemon --num-devices=4 --audio-driver=pulse
cdemu-daemon --num-devices=2 --bus=system --logfile=/tmp/cdemu-daemon.log


The daemon's settings can be collected in a configuration file, which is passed to the daemon via --config-file option. Configuration file contains key=value pairs that are contained in a single [settings] section. The keys in configuration file correspond to the long names of command-line switches.

If an option is specified in both configuration file and on command-line, the latter takes precedence.

If the specified configuration file does not exist, it is silently ignored. If the specified configuration file is invalid (e.g., has invalid syntax, or does not contain a section), an error is raised.


Saving the following configuration to a file and passing it to the daemon via --config-file is equivalent to passing --num-devices=2 --audio-driver=pulse directly to the daemon:



Rok Mandeljc <>

CDEmu project's web page:

CDEmu project's mailing list:

April 5, 2021