Managing Serviceguard Fifteenth Edition, reprinted May 2008

Building an HA Cluster Configuration
Preparing Your Systems
Chapter 5 211
pvdisplay <lock device file name>
The I/O Timeout value should be displayed as “default.” To set the IO
Timeout back to the default value, run the command:
pvchange -t 0 <lock device file name>
The use of a dual cluster lock is only allowed with certain specific
configurations of hardware. Refer to the discussion in Chapter 3 on “Dual
Cluster Lock.” For instructions on setting up a lock disk, see “Specifying
a Lock Disk” on page 229.
Backing Up Cluster Lock Disk Information
After you configure the cluster and create the cluster lock volume group
and physical volume, you should create a backup of the volume group
configuration data on each lock volume group. Use the vgcfgbackup
command for each lock volume group you have configured, and save the
backup file in case the lock configuration must be restored to a new disk
with the vgcfgrestore command following a disk failure.
NOTE You must use the vgcfgbackup and vgcfgrestore commands to back up
and restore the lock volume group configuration data regardless of how
you create the lock volume group.
Setting Up a Lock LUN
LUN stands for Logical Unit Number. The term can refer to a single
physical disk, but these days is more often used in a SAN (Storage Area
Network) or NAS (Network-Attached Storage) context to denote a virtual
entity derived from one or more physical disks.
Keep the following points in mind when choosing a device for a lock
LUN:
• All the cluster nodes must be physically connected to the lock LUN.
• A lock LUN must be a block device.
• All existing data on the LUN will be destroyed when you configure it
as a lock LUN.