HP Veritas Volume Manager 5.0 -UX 11i v3 manual Handling conflicting configuration copies

190Creating and administering disk groups

Handling conflicting configuration copies

You can use the following command to discover the maximum number of volumes that are supported by VxVM on a Linux host:

#cat /proc/sys/vxvm/vxio/vol_max_volumes 4079

See the vxdg(1M) manual page for more information.

Handling conflicting configuration copies

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.

Example of a serial split brain condition in a 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 397. 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 194 describes how to correct such problems.

A campus cluster (also known as a stretch cluster or remote mirror configuration) typically consists of a 2-node cluster where each component (server, switch and storage) of the cluster exists in a separate building. Figure 4- 1 illustrates 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.