cmdisklock(1m)							cmdisklock(1m)

NAME
       cmdisklock - manage Serviceguard cluster lock devices.

SYNOPSIS
       cmdisklock check path
       cmdisklock [-f] reset path

DESCRIPTION
       cmdisklock 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 VALUE
       cmdisklock returns the following values:

	      0	   Successful completion.
	      1	   The	disk is inaccessible or is not recognized as a cluster
		   lock.

AUTHOR
       cmdisklock was developed by HP.

SEE ALSO
       cmapplyconf(1m), cmviewcl(1m), vgcfgbackup(1m), vgcfgrestore(1m)

		    Requires Optional Serviceguard Software	cmdisklock(1m)

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