Managing Serviceguard Sixteenth Edition, March 2009

Replacing a Lock Disk
You can replace an unusable lock disk while the cluster is running. You can do this
without any cluster reconfiguration if you do not change the devicefile name (Device
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 disk under the HP-UX 11i v3 agile addressing
scheme (see About Device File Names (Device Special Files)” (page 107)), 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 device. See the section Replacing a Bad Disk in the Logical Volume
Management volume of the HP-UX System Administrator’s Guide, posted at http://
docs.hp.com -> 11i v3 -> System Administration. See also the section on
io_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 do not use the existing DSF for the new device, you must change the name of
the DSF in the cluster configuration file and re-apply the configuration; see “Updating
the Cluster Lock Disk Configuration Online” (page 327). Do this after running
vgcfgrestore as described below.
CAUTION: Before you start, make sure that all nodes have logged a message in syslog
saying that the lock disk is corrupt or unusable.
Replace a failed LVM lock disk in the same way as you replace a data disk. If you are
using a dedicated lock disk (one with no user data on it), then you need to use only one
LVM command, for example:
vgcfgrestore -n /dev/vg_lock /dev/dsk/c2t3d0
Serviceguard checks the lock disk every 75 seconds. After using the vgcfgrestore
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 disk is healthy again.
NOTE: If you restore or recreate the volume group for the lock disk and you need to
re-create the cluster lock (for example if no vgcfgbackup is available), you can run
cmdisklock to re-create the lock. See the cmdisklock (1m) manpage for more
information.
Replacing a Lock LUN
You can replace an unusable lock disk while the cluster is running. You can do this
without any cluster reconfiguration if you do not change the devicefile name (Device
366 Troubleshooting Your Cluster