cmdisklock(1m)cmdisklock(1m)NAMEcmdisklock - manage Serviceguard cluster lock devices.
SYNOPSIScmdisklock check path
cmdisklock [-f] reset path
DESCRIPTIONcmdisklock is a tool to check the current state of a Serviceguard clus‐
ter lock device. It can also be used to reset the state of the cluster
lock device. The need to reset the cluster lock device state could
arise if the cluster lock device is replaced or becomes corrupt.
A cluster lock device can be either an HP-UX LVM cluster lock or a
cluster lock LUN device. HP-UX LVM cluster locks exist only on a disk
in an LVM volume group. Cluster lock LUNs exist only on disks dedi‐
cated to cluster lock. cmdisklock is useful for checking either type
of cluster lock and for re-initializing cluster lock LUN devices after
a failure or corruption.
NOTE
To restore an HP-UX LVM cluster lock, use vgcfgrestore. cmdisklock
will fail until vgcfgrestore is run, and cmdisklock is unnecessary as
long as vgcfgbackup was done after the cluster lock was initialized.
See the Managing Serviceguard manual for details.
The syntax of the path option depends on the type of lock. For HP-UX
LVM cluster lock disks, the syntax is VG:PV (for example:
/dev/vglock:/dev/dsk/c0t0d2). For cluster lock LUN disks, the path is
the disk device path. For example, /dev/sdd1 (on Linux) or
/dev/dsk/c0t1d2 (on HP-UX).
Options
cmdisklock supports the following options:
check Check the current state of the cluster lock
device and report the results.
reset Reset (initialize) the state of the cluster
lock device. This operation should only be
performed on a cluster lock LUN device. For
HP-UX LVM cluster lock, use vgcfgrestore as
documented in the Managing Serviceguard manual.
After performing a reset, a check can be used
to verify that the lock is cleared.
EXAMPLES
If the cluster lock LUN device becomes corrupted and the cluster is up,
messages like the following will appear in syslog.
Mar 15 12:20:41 usb cmdisklockd[17599]: WARNING: Cluster lock LUN
/dev/dsk/c0t1d2 is corrupt: bad label. Until this situation is cor‐
rected, a single failure could cause all nodes in the cluster to crash.
Mar 15 12:20:41 usb cmdisklockd[17599]: After ensuring that all active
nodes in the cluster have logged this message, run 'cmdisklock reset
/dev/dsk/c0t1d2' to repair
Mar 15 12:20:41 usb cmdisklockd[17599]: Cluster lock disk
/dev/dsk/c0t1d2 is inaccessible
Once the above messages appear in syslog on all running nodes, the fol‐
lowing command will re-initialize the cluster lock LUN:
ucd:/> cmdisklock reset /dev/dsk/c0t1d2
WARNING: Cluster lock LUN /dev/dsk/c0t1d2 is corrupt: bad label. Until
this situation is corrected, a single failure could cause all nodes in
the cluster to crash.
After ensuring that all active nodes in the cluster have logged this
message, run 'cmdisklock reset /dev/dsk/c0t1d2' to repair
/dev/dsk/c0t1d2 is inaccessible
Resetting cluster lock device /dev/dsk/c0t1d2
Cluster lock reset completed
/dev/dsk/c0t1d2 is accessible
cleared
After the lock is restored, a message like the following appears in
syslog:
Mar 15 12:23:11 usb cmdisklockd[17599]: Cluster lock disk
/dev/dsk/c0t1d2 is accessible
WARNINGS
CAUTION
For cluster lock LUN, reset is a potentially destructive operation.
While cmdisklock checks for known volume manager and file system use
(overridden by -f), it does not validate that the device to be reset is
actually used by any cluster. If -f is used on the wrong device file,
loss of data may result.
CAUTION
Care should be taken when doing a reset when the cluster is active as
there is a remote possibility that the cluster will partition right
when this command is run and both nodes could end up thinking they have
successfully acquired the lock. To avoid this situation, make sure
cmcld has logged a message in syslog on all running nodes saying the
device is inaccessble, before performing a reset. Note that it is safe
to run cmdisklock when the cluster is down.
RETURN VALUEcmdisklock returns the following values:
0 Successful completion.
1 The disk is inaccessible or is not recognized as a cluster
lock.
AUTHORcmdisklock was developed by HP.
SEE ALSOcmapplyconf(1m), cmviewcl(1m), vgcfgbackup(1m), vgcfgrestore(1m)
Requires Optional Serviceguard Software cmdisklock(1m)