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

Chapter 16: SAN Maintenance 157
• Repeated I/O errors when the server tries to write to a PSFS journal.
The server then loses access to the affected filesystem. When the disk
experiencing the I/O errors is fixed, the server will automatically
regain access to the filesystem.
The HP CFS Management Console typically displays an alert message
when a server loses access to the SAN. (See Appendix B for more
information about these messages.)
Membership Partitions
HP Clustered File System uses a set of membership partitions to control
access to the SAN and to store the device naming database, which
includes the global device names for SAN disks imported into the cluster.
Typically, the membership partitions are created when you install HP
Clustered File System.
When a membership partition is placed under HP Clustered File System
control, write access is disabled to prevent accidental corruption from
other applications.
The following commands can be useful in diagnosing or repairing
problems with the membership partitions:
•The mxsanlk command reports the status of the SAN ownership locks
used to control access to the SAN. These locks are stored on the
membership partitions.
•The mprepair command can be used to repair membership partitions.
Display the Status of SAN Ownership Locks
HP Clustered File System uses a set of disk-based data structures called
SANlocks to protect filesystem integrity. If a problem causes a cluster to
split into two or more network partitions, the SANlocks ensure that only
one of the resulting network partitions has access to the SAN.
Each SANlock is stored in a membership partition. Before a cluster can
begin accessing the SAN, it must first acquire a majority of the SANlocks.
The SANlocks are acquired in order.