HP Serviceguard Extension for RAC (SGeRAC) Using CVM, Preparing the Cluster for Use with CVM

IMPORTANT: After creating these files, use the vxedit command to change the ownership of the raw volume files to oracle and the group membership to dba, and to change the permissions to 660. Example:

#cd /dev/vx/rdsk/ops_dg

#vxedit -g ops_dg set user=oracle *

#vxedit -g ops_dg set group=dba *

#vxedit -g ops_dg set mode=660 *

The logical volumes are now available on the primary node, and the raw logical volume names can now be used by the Oracle DBA.

CAUTION: Once you create the disk group and mount point packages, you must administer the cluster with CFS commands, including cfsdgadm, cfsmntadm, cfsmount, and cfsumount. You must not use the HP-UX mount or umount command to provide or remove access to a shared file system in a CFS environment. Using these HP-UX commands under these circumstances is not supported. Use cfsmount and cfsumount instead.

If you use the HP-UX mount and umount commands, serious problems could occur, such as writing to the local file system instead of the cluster file system. Non-CFS commands could cause conflicts with subsequent CFS command operations on the file system or the Serviceguard packages, and will not create an appropriate multi-node package—cluster packages will not be aware of file system changes.

Mirror Detachment Policies with CVM

The required CVM disk mirror detachment policy is "global"—as soon as one node cannot see a specific mirror copy (plex), all nodes cannot see it as well. The alternate policy is "local"—if one node cannot see a specific mirror copy, then CVM will deactivate access to the volume for that node only.

This policy can be reset on a disk group basis by using the vxedit command, as follows:

#vxedit set diskdetpolicy=global <DiskGroupName>

NOTE: The specific commands for creating mirrored and multipath storage using CVM are described in the HP-UX documentation for the Veritas Volume Manager.

Using CVM 5.x

This section has information on how to prepare the cluster and the system multi-node package with CVM 5.x (on HP-UX releases that support them). See “About Veritas CFS and CVM from Symantec” (page 15).

Preparing the Cluster for Use with CVM 5.x

To use the Veritas Cluster Volume Manager (CVM) version 5.x, the cluster must be running with a special CVM package. Before you create disk groups, the cluster must be configured and running.

NOTE: Cluster configuration is described in the previous section.

To prepare the cluster for CVM disk group configuration, you need to ensure that only one heartbeat subnet is configured. Then, use the following command, which creates the special package that communicates cluster information to CVM:

#cmapplyconf -P /etc/cmcluster/cvm/VxVM-CVM-pkg.conf

WARNING! The above file should never be edited.

Creating a Storage Infrastructure with CVM 55