Managing Serviceguard Nineteenth Edition, Reprinted June 2011

IMPORTANT: If you need to replace a disk under the HP-UX 11i v3 agile addressing scheme,
also used by cDSFs (see “About Device File Names (Device Special Files)” (page 77) and “About
Cluster-wide Device Special Files (cDSFs)” (page 99)), 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://www.hp.com/go/hpux-core-docs. See also the section on io_redirect_dsf
at the same address.
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 281). 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 Special File, or DSF); or,
if you need to change the DSF, you can do the necessary reconfiguration while the cluster is
running.
312 Troubleshooting Your Cluster