Veritas Volume Manager 4.1 Administrator's Guide (HP-UX 11i v3, February 2007)

Handling Conflicting Configuration Copies in a Disk Group
150 VERITAS Volume Manager Administrator’s Guide
Handling Conflicting Configuration Copies in a Disk Group
If an incomplete disk group is imported on several different systems, this can create
inconsistencies in the disk group configuration copies that you may need to resolve
manually. This section and following sections describe how such a condition can occur,
and how to correct it. (When the condition occurs in a cluster that has been split, it is
usually referred to as a serial split brain condition).
Note The procedures given here require that the version number of the disk group is at
least 110. However, these procedures cannot be applied to SAN disk groups.
Example of a Serial Split Brain Condition in a Campus Cluster
Note This section presents an example of how a serial split brain condition might occur
for a shared disk group in a cluster. For more information about shared disk groups
in clusters, see “Administering Cluster Functionality” on page 347. Conflicts
between configuration copies can also occur for private disk groups in clustered
and non-clustered configurations where the disk groups have been partially
imported on different systems. The procedure in “Correcting Conflicting
Configuration Information” on page 154 describes how to correct such problems.
A campus cluster (also known as a stretch cluster) typically consists of a 2-node cluster
where each component (server, switch and storage) of the cluster exists in a separate
building. This is illustrated in “Typical Arrangement of a 2-node Campus Cluster,” which
shows a 2-node cluster with node 0, a fibre channel switch and disk enclosure enc0 in
building A, and node 1, another switch and enclosure enc1 in building B. The fibre
channel connectivity is multiply redundant to implement redundant-loop access between
each node and each enclosure. As usual, the two nodes are also linked by a redundant
private network.