A.3.2. Commands and Interfaces that Support udev
Table A.2, “dmsetup Commands to Support udev” summarizes the
dmsetup
commands that support udev
integration.
Command | Description |
---|---|
dmsetup udevcomplete | Used to notify that udev has completed processing the rules and unlocks waiting process (called from within udev rules in 95-dm-notify.rules ). |
dmsetup udevcomplete_all | Used for debugging purposes to manually unlock all waiting processes. |
dmsetup udevcookies | Used for debugging purposes, to show all existing cookies (system-wide semaphores). |
dmsetup udevcreatecookie | Used to create a cookie (semaphore) manually. This is useful to run more processes under one synchronization resource. |
dmsetup udevreleasecookie | Used to wait for all udev processing related to all processes put under that one synchronization cookie. |
The
dmsetup
options that support udev
integration are as follows.
--udevcookie
- Needs to be defined for all dmsetup processes we would like to add into a udev transaction. It is used in conjunction with
udevcreatecookie
andudevreleasecookie
:COOKIE=$(dmsetup udevcreatecookie) dmsetup command --udevcookie $COOKIE .... dmsetup command --udevcookie $COOKIE .... .... dmsetup command --udevcookie $COOKIE .... dmsetup udevreleasecookie --udevcookie $COOKIE
Besides using the--udevcookie
option, you can just export the variable into an environment of the process:export DM_UDEV_COOKIE=$(dmsetup udevcreatecookie) dmsetup command ... dmsetup command ... ... dmsetup command ...
--noudevrules
- Disables udev rules. Nodes/symlinks will be created by
libdevmapper
itself (the old way). This option is for debugging purposes, ifudev
does not work correctly. --noudevsync
- Disables
udev
synchronization. This is also for debugging purposes.
For more information on the
dmsetup
and its options, see the dmsetup
(8) man page.
The LVM commands support the following options that support
udev
integration:
--noudevrules
: as for thedmsetup
command, disablesudev
rules.--noudevsync
: as for thedmsetup
command, disablesudev
synchronization.
The
lvm.conf
file includes the following options that support udev
integration:
udev_rules
: enables/disablesudev_rules
for all LVM2 commands globally.udev_sync
: enables/disablesudev
synchronization for all LVM commands globally.
For more information on the
lvm.conf
file options, see the inline comments in the lvm.conf
file.