Veritas Storage Foundation 5.1 SP1 Cluster File System Installation Guide (5900-1510, April 2011)

The metanode interface that HP-UX provides does not meet the SCSI-3 PR
requirements for the I/O fencing feature. You can configure coordinator disks
to use Veritas Volume Manager Dynamic Multi-pathing (DMP) feature.
See the Veritas Volume Manager Administrator’s Guide.
■ Coordination point servers
The coordination point server (CP server) is a software solution which runs
on a remote system or cluster. CP server provides arbitration functionality by
allowing the SFCFS cluster nodes to perform the following tasks:
■ Self-register to become a member of an active SFCFS cluster (registered
with CP server) with access to the data drives
■ Check which other nodes are registered as members of this activeSFCFS
cluster
■ Self-unregister from this active SFCFS cluster
■ Forcefully unregister other nodes (preempt) as members of this active
SFCFS cluster
In short, the CP server functions as another arbitration mechanism that
integrates within the existing I/O fencing module.
Note: With the CP server, the fencing arbitration logic still remains on the
SFCFS cluster.
Multiple SFCFS clusters running different operating systems can
simultaneously access the CP server. TCP/IP based communication is used
between the CP server and the SFCFS clusters.
About preferred fencing
The I/O fencing driver uses coordination points to prevent split-brain in a VCS
cluster. By default, the fencing driver favors the subcluster with maximum number
of nodes during the race for coordination points. With the preferred fencing
feature, you can specify how the fencing driver must determine the surviving
subcluster.
You can configure the preferred fencing policy using the cluster-level attribute
PreferredFencingPolicy as follows:
■ Enable system-based preferred fencing policy to give preference to high
capacity systems.
■ Enable group-based preferred fencing policy to give preference to service
groups for high priority applications.
85Preparing to configure SFCFS
About I/O fencing components