Configuring Cluster Support

The VERITAS Volume Manager software includes an optional cluster feature that enables it to be used in a cluster environment. The cluster functionality in VERITAS Volume Manager allows multiple hosts to simultaneously access and manage a set of disks under VERITAS Volume Manager control. A cluster is a set of hosts sharing a set of disks; each host is referred to as a node in the cluster.

For information about enabling cluster functionality in VERITAS Volume Manager, refer to the VERITAS Storage Solutions Getting Started Guide.

Configuring Shared Disk Groups

This section describes how to configure shared disks in a cluster. If you are installing VERITAS Volume Manager for the first time or adding disks to an existing cluster, you need to configure new shared disks.

If you are setting up VERITAS Volume Manager for the first time, configure the shared disks using the following procedure:

1. Start the cluster on one node only to prevent access by other nodes.
2. On one node, run the vxdiskadm program and choose option 1 to initialize new disks. When asked to add these disks to a disk group, choose none to leave the disks for future use.
3. On other nodes in the cluster, run vxdctl enable to see the newly initialized disks.
4. From the master node, create disk groups on the shared disks. To determine if a node is a master or slave, run the command vxdctl -c mode.

   Use the vxdg command or VEA to create disk groups. If you use the vxdg command, specify the -s option to create shared disk groups.

5. From the master node only, use vxassist or VEA to create volumes in the disk groups.

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     Note    RAID-5 volumes are not supported for sharing in a cluster.

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6. If the cluster is only running with one node, bring up the other cluster nodes. Enter the vxdg list command on each node to display the shared disk groups.

Converting Existing VxVM Disk Groups to Shared Disk Groups

To convert existing disk groups to shared disk groups:

1. Start the cluster on one node only to prevent access by other nodes.
2. Configure the disk groups using the following procedure.

   To list all disk groups, use the following command:

   
     # vxdg list

   To deport the disk groups that are to be shared, use the following command:

   
     # vxdg deport diskgroup

   To import disk groups to be shared, use the following command:

   
     # vxdg -s import diskgroup

   This procedure marks the disks in the shared disk groups as shared and stamps them with the ID of the cluster, enabling other nodes to recognize the shared disks.

   If dirty region logs exist, ensure they are active. If not, replace them with larger ones.

   To display the shared flag for all the shared disk groups, use the following command:

   
     # vxdg list

   The disk groups are now ready to be shared.

3. Bring up the other cluster nodes. Enter the vxdg list command on each node to display the shared disk groups. This command displays the same list of shared disk groups displayed earlier.

For information on converting disk groups in a VERITAS Cluster File System (CFS) environment, see the VERITAS Cluster File System Installation and Configuration Guide.