Managing Serviceguard Seventeenth Edition, First Reprint December 2009

Special File, or DSF); or, if you need to change the DSF, you can do the necessary
reconfiguration while the cluster is running.
IMPORTANT: If you need to replace a LUN under the HP-UX 11i v3 agile addressing
scheme (see “About Device File Names (Device Special Files)” (page 106)), and you use
the same DSF, you may need to use the io_redirect_dsf(1M) command to reassign
the existing DSF to the new device, depending on whether the operation changes the
WWID of the LUN; see the section onio_redirect_dsf in the white paper The Next
Generation Mass Storage Stack under Network and Systems Management ->
Storage Area Management on docs.hp.com.
If you are not able to use the existing DSF for the new device, or you decide not to, you
must change the name of the DSF in the cluster configuration file and re-apply the
configuration; see “Updating the Cluster Lock LUN Configuration Online” (page 329).
Do this after running vgcfgrestore as described below.
CAUTION: Before you start, make sure that all nodes have logged a message such as
the following in syslog:
WARNING: Cluster lock LUN /dev/dsk/c0t1d1 is corrupt: bad label.
Until this situation is corrected, a single failure could cause
all nodes in the cluster to crash.
Once all nodes have logged this message, use a command such as the following to
specify the new cluster lock LUN:
cmdisklock reset /dev/dsk/c0t1d1
cmdisklock checks that the specified device is not in use by LVM, VxVM, ASM, or
the file system, and will fail if the device has a label marking it as in use by any of those
subsystems. cmdisklock -f overrides this check.
CAUTION: You are responsible for determining that the device is not being used by
any subsystem on any node connected to the device before using cmdisklock -f. If
you use cmdisklock -f without taking this precaution, you could lose data.
NOTE: cmdisklock is needed only when you are repairing or replacing a lock LUN
or lock disk; see the cmdisklock (1m) manpage for more information.
Serviceguard checks the lock LUN every 75 seconds. After using the cmdisklock
command, review the syslog file of an active cluster node for not more than 75 seconds.
By this time you should see a message showing that the lock LUN is healthy again.
Replacing Disks 371