Managing Serviceguard Fifteenth Edition, reprinted May 2008

Troubleshooting Your Cluster
Replacing Disks
Chapter 8416
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.
On-line Hardware Maintenance with In-line SCSI
Terminator
In some shared SCSI bus configurations, on-line SCSI disk controller
hardware repairs can be made if HP in-line terminator (ILT) cables are
used. In-line terminator cables are supported with most SCSI-2
Fast-Wide configurations.
In-line terminator cables are supported with Ultra2 SCSI host bus
adapters only when used with the SC10 disk enclosure. This is because
the SC10 operates at slower SCSI bus speeds, which are safe for the use
of ILT cables. In-line terminator cables are not supported for use in any
Ultra160 or Ultra3 SCSI configuration, since the higher SCSI bus speeds
can cause silent data corruption when the ILT cables are used.