CLVMD(8)                   System Manager's Manual                  CLVMD(8)

NAME         top

       clvmd — cluster LVM daemon

SYNOPSIS         top

       clvmd [-C] [-d [value]] [-E lock_uuid] [-f] [-h] [-I cluster_manager]
       [-R] [-S] [-t timeout] [-T start_timeout] [-V]

DESCRIPTION         top

       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

OPTIONS         top

              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
              with -d.
              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, eg:
              clvmd -d2

       -d [value]
              Set debug logging level.  If -d is specified without a value
              then 1 is assumed. Value can be:
              0 — Disabled
              1 — Sends debug logs to stderr (implies -f)
              2 — Sends debug logs to syslog(3)

       -E lock_uuid
              Pass lock uuid to be reacquired exclusively when clvmd is

              Don't fork, run in the foreground.

              Show help information.

       -I cluster_manager
              Selects the cluster manager to use for locking and internal
              communications. As it is quite possible to have multiple
              managers available on the same system you might have to
              manually specify this option to override the search.

              By default, omit -I is equivalent to -Iauto.  Clvmd will use
              the first cluster manager that succeeds, and it checks them in
              a predefined order cman, corosync, openais.  The available
              managers will be listed by order as part of the clvmd -h

              Tells all the running instance of clvmd in the cluster to
              reload their device cache and re-read the lvm configuration
              file lvm.conf(5). This command should be run whenever the
              devices on a cluster system are changed.

              Tells the running clvmd to exit and reexecute itself, for
              example at the end of a package upgrade. The new instance is
              instructed to reacquire any locks in the same state as they
              were previously held. (Alternative methods of restarting the
              daemon have the side effect of changing exclusive LV locks
              into shared locks.)

       -t timeout
              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 60

       -T start_timeout
              Specifies the start 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 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.

              Display the version of the cluster LVM daemon.

NOTES         top

       In a clustered VG, clvmd is used for activation, and the following
       values are possible with lvchange/vgchange -a:

       y|sy   clvmd activates the LV in shared mode (with a shared lock),
              allowing multiple nodes to activate the LV concurrently.  If
              the LV type prohibits shared access, such as an LV with a
              snapshot, an exclusive lock is automatically used instead.
              clvmd attempts to activate the LV concurrently on all nodes.

       ey     clvmd activates the LV in exclusive mode (with an exclusive
              lock), allowing a single node to activate the LV.  clvmd
              attempts to activate the LV concurrently on all nodes, but
              only one will succeed.

       ly     clvmd attempts to activate the LV only on the local node.  If
              the LV type allows concurrent access, then shared mode is
              used, otherwise exclusive.

       n      clvmd attempts to deactivate the LV on all nodes.

       ln     clvmd attempts to deactivate the LV on the local node.


              The CLVMD binary to use when clvmd restart is requested.
              Defaults to /data/lvmtest/usr/sbin/clvmd.

              The LVM2 binary to use.  Defaults to /data/lvmtest/sbin/lvm.

FILES         top


SEE ALSO         top

       syslog(3), lvm.conf(5), lvm(8)

COLOPHON         top

       This page is part of the lvm2 (Logical Volume Manager 2) project.
       Information about the project can be found at 
       ⟨⟩.  If you have a bug report for this
       manual page, send it to  This page was obtained
       from the project's upstream Git repository 
       ⟨git://⟩ on 2017-05-03.  If you discover
       any rendering problems in this HTML version of the page, or you
       believe there is a better or more up-to-date source for the page, or
       you have corrections or improvements to the information in this
       COLOPHON (which is not part of the original manual page), send a mail

Red Hat Inc        LVM TOOLS 2.02.171(2)-git (2017-04-13)           CLVMD(8)

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