4.0.0 HP Polyserve Matrix Server Administration Guide (T5392-96052, March 2010)

Journaling filesystem
When you initiate certain filesystem operations such as creating, opening, or moving
a file or modifying its size, the filesystem writes the metadata, or structural information,
for that event to a transaction journal. The filesystem then performs the operation.
If a server using the filesystem should crash during an operation, the journal is
replayed and any journaled operations in progress at the time of the crash are
completed. This procedure ensures that the structure of the filesystem is consistent.
Users on other servers will experience only a slight delay in filesystem operations
during the recovery.
Server registry
Matrix Server uses a registry to control server access to PSFS filesystems on the SAN
disks imported into the cluster. A server is added to the registry when it mounts its
first PSFS filesystem.
NOTE:
This registry is different from the Windows registry. The Matrix Server registry is
used only for PSFS filesystem control and is located on the membership partitions
on shared disk.
Under normal operations, a server remains in the registry until it either unmounts its
last PSFS filesystem or leaves the cluster. However, if a server crashes or loses
communication with the cluster and that server is in the registry (indicating that it had
active PSFS mounts), Matrix Server will remove the server’s access to the filesystems.
When this situation occurs, an alert will appear on the PolyServe Management
Console, NOSAN will be reported for the server, and a message will be written to
the Matrix Server event log. You will need to reboot the server to restore its access.
After the server is rebooted and rejoins the cluster, it is deleted from the registry.
When the server again mounts a PSFS filesystem, it will be added back into the
registry.
Filesystem management and integrity
Matrix Server uses the SANPulse process to manage PSFS filesystems. SANPulse
performs the following tasks:
Configure PSFS filesystems102