HP StorageWorks Clustered File System 3.2.1 Windows Storage Server Edition Administration Guide (February 2006)

Chapter 6: Configure the SAN 44
As part of managing shared SAN devices, the SCL also gives each disk a
globally unique device identifier that all servers in the cluster use to
access the device. Although the identifiers (such as psd2 or psd2p6)
appear on certain HP CFS Management Console windows, they are
generally only needed for internal use by HP Clustered File System.
Device Database and Membership Partitions
The SCL stores the device identifier and physical UID for each imported
disk in a device database. When you installed HP Clustered File System,
you specified a set of SAN partitions to be used for the database and for
other functions related to SAN control. These partitions are called
membership partitions and are automatically imported into the cluster. (For
more information about these partitions, see “Manage Membership
Partitions with mprepair” on page 160.)
HP Clustered File System creates the device database on one of the
membership partitions and then replicates it to the other partitions. The
database must be present for a cluster to form. To ensure that the
database is always available, the recommended configuration is a three-
way mirror.
You can use the mprepair utility to fix any problems with the
membership partitions.
Import SAN Disks
SAN disks to be used for PSFS filesystems must be imported into the
cluster. This step gives the cluster control over access to the disks. Before
importing disks, you should be aware of the following:
• If servers from multiple clusters can access the SAN via a shared FC
fabric, avoid importing the same disk into more than one cluster.
Filesystem corruption can occur when different clusters attempt to
share the same filesystem.
• Only basic disks can be imported. Dynamic disks are not supported.
• Shared disks must be partitioned before they are imported into the
cluster. If there is not a partition table in place on the disk, you will not
be able to access it via HP Clustered File System.