3.6.1 HP PolyServe Matrix Server Administration Guide (T5392-96018, August 2008)

Chapter 20: SAN Maintenance 264
before making the partition table changes and then reenabling access
afterwards.
If you should later need to repartition a disk containing a membership
partition, you will need to stop Matrix Server before you change the
layout. While the matrix is stopped, you will not be able to access other
disks in the matrix. You will also need to take one of the above steps to
force the servers in the matrix to recognize the changes.
Display the Status of SAN Ownership Locks
Matrix Server uses a set of disk-based data structures called SANlocks to
protect filesystem integrity. If a problem causes a matrix 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 matrix can
begin accessing the SAN, it must first acquire a majority of the SANlocks.
The SANlocks are acquired in order.
mxsanlk displays the status of the SANlock stored in each membership
partition. It can be used to determine whether any of the membership
partitions need to be repaired. Also, if a network partition occurs,
mxsanlk can be used to determine which network partition has control of
the SAN.
When you invoke mxsanlk, it checks for the Storage Device Monitor
Pulse (SDMP) process. This process is responsible for grabbing and
maintaining the locks on the membership partitions. The SDMP
administrator is the administrator for the matrix to which the host
belongs.
Following is some sample output from mxsanlk. The command was
issued on host 10.10.30.3 and there are three membership partitions.