bionic (8) clvmd.8.gz

Provided by: clvm_2.02.176-4.1ubuntu3.18.04.3_amd64 bug

NAME

       clvmd — cluster LVM daemon

SYNOPSIS

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

DESCRIPTION

       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.

       Also see lvmlockd(8) for a newer method of using LVM on shared storage.

OPTIONS

       -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 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
              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 restarted.

       -f
              Don't fork, run in the foreground.

       -h
              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 output.

       -R
              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.

       -S
              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 seconds.

       -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.

       -V
              Display the version of the cluster LVM daemon.

NOTES

   Activation
       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.

ENVIRONMENT VARIABLES

       LVM_CLVMD_BINARY
              The CLVMD binary to use when clvmd restart is requested.  Defaults to /clvmd.

       LVM_BINARY
              The LVM2 binary to use.  Defaults to /lvm.

FILES

       /clvmd
       /lvm

SEE ALSO

       syslog(3), lvm.conf(5), lvm(8), lvmlockd(8), lvmsystemid(7)