clvmd - cluster LVM daemon
clvmd [-d [<value>]] [-C] [-h] [-R] [-t <timeout>] [-T <start timeout>]
clvmd is the daemon that distributes LVM metadata updates around a
cluster. It must be running on all nodes in the cluster and will give
an error if a node in the cluster does not have this daemon running.
Enable debug logging. Value can be 0, 1 or 2.
0 disables debug logging in a running clvmd
1 sends debug logs to stderr (clvmd will not fork in this case)
2 sends debug logs to syslog
If -d is specified without a value then 1 is assumed if you are
starting a new clvmd, 2 if you are enabling debug in a running
-C Only valid if -d is also specified. Tells all clvmds in a
cluster to enable/disable debug logging. Without this switch,
only the local clvmd will change its debug level to that given
This does not work correctly if specified on the command-line
that starts clvmd. If you want to start clvmd and enable
cluster-wide logging then the command needs to be issued twice,
Specifies the timeout for commands to run around the cluster.
This should not be so small that commands with many disk updates
to do will fail, so you may need to increase this on systems
with very large disk farms. The default is 30 seconds.
-T <start timeout>
Specifies the timeout for clvmd daemon startup. If the daemon
does not report that it has started up within this time then the
parent command will exit with status of 5. This does NOT mean
that clvmd has not started! What it means is that the startup of
clvmd has been delayed for some reason; the most likely cause of
this is an inquorate cluster though it could be due to locking
latencies on a cluster with large numbers of logical volumes. If
you get the return code of 5 it is usually not necessary to
restart clvmd - it will start as soon as that blockage has
cleared. This flag is to allow startup scripts to exit in a
timely fashion even if the cluster is stalled for some reason.
The default is 0 (no timeout) and the value is in seconds. Don’t
set this too small or you will experience spurious errors. 10 or
20 seconds might be sensible.
This timeout will be ignored if you start clvmd with the -d
-R Tells all the running clvmds in the cluster to reload their
device cache and re-read the lvm configuration file. This
command should be run whenever the devices on a cluster system
-I Selects the cluster manager to use for locking and internal
communications, the available managers will be listed as part of
the ’clvmd -h’ output. clvmd will use the first cluster manager
that succeeds, and it checks them in the order
cman,gulm,corosync,openais. As it is quite possible to have (eg)
corosync and cman available on the same system you might have to
manually specify this option to override the search.
-V Display the version of the cluster LVM daemon.