Managing Serviceguard A.11.20, March 2013

• A lock LUN cannot be used in a dual-lock configuration.
• You do not need to back up the lock LUN data, and in fact there is no way to do so.
A lock LUN needs only a small amount of storage, about 100 KB.
• If you are using a disk array, create the smallest LUN the array will allow, or, on an HP Integrity
server, you can partition a LUN; see “Creating a Disk Partition on an HP Integrity System”.
• If you are using individual disks, use either a small disk, or a portion of a disk. On an HP
Integrity server, you can partition a disk; see “Creating a Disk Partition on an HP Integrity
System”.
IMPORTANT: On HP 9000 systems, there is no means of partitioning a disk or LUN, so you
will need to dedicate an entire small disk or LUN for the lock LUN. This means that in a mixed
cluster containing both Integrity and HP-PA systems, you must also use an entire disk or LUN;
if you partition the device as described below, the HP-PA nodes will not be able to see the
partitions.
Creating a Disk Partition on an HP Integrity System
You can use the idisk utility to create a partition for a lock LUN in a cluster that will contain only
HP Integrity servers. Use the procedure that follows; see the idisk (1m) manpage for more
information. Do this on one of the nodes in the cluster that will use this lock LUN.
CAUTION: Before you start, make sure the disk or LUN that is to be partitioned has no data on
it that you need. idisk will destroy any existing data.
1. Use a text editor to create a file that contains the partition information. You need to create at
least three partitions, for example:
3
EFI 100MB
HPUX 1MB
HPUX 100%
This defines:
• A 100 MB EFI (Extensible Firmware Interface) partition (this is required).
• A 1 MB partition that can be used for the lock LUN.
• A third partition that consumes the remainder of the disk is and can be used for whatever
purpose you like.
2. Save the file; for example you might call it partition.txt.
3. Create the partition; for example (using partition.txt as input):
/usr/sbin/idisk -w -p -f partition.txt /dev/rdsk/c1t4d0
Or, on an HP-UX 11i v3 system using agile addressing (see “About Device File Names (Device
Special Files)” (page 81):
/usr/sbin/idisk -w -p -f partition.txt /dev/rdisk/disk12
NOTE: Device files for partitions cannot be cluster-wide DSFs (cDSFs). For more information
about cDSFs, see “About Cluster-wide Device Special Files (cDSFs)” (page 109).
This will create three device files, for example
/dev/dsk/c1t4d0s1, /dev/dsk/c1t4d0s2, and /dev/dsk/c1t4d0s3
or:
/dev/disk/disk12_p1, /dev/disk/disk12_p2, and /dev/disk/disk12_p3
Preparing Your Systems 179