SPARC: Setting Up a Root Disk Group Overview

For VxVM 4.0, the creation of a root disk group is optional. If you do not intend to create a root disk group, proceed to SPARC: How to Install VERITAS Volume Manager Software Only.

For VxVM 3.5 and earlier, each cluster node requires the creation of a root disk group after VxVM is installed. This disk group is used by VxVM to store configuration information, and has the following restrictions.

• Access to a node's root disk group must be restricted to only that node.

• Remote nodes must never access data stored in another node's root disk group.

• Do not use the scconf(1M) command to register the root disk group as a disk device group.

• Whenever possible, configure the root disk group for each node on a nonshared disk.

Sun Cluster software supports the following methods to configure the root disk group.

• Encapsulate the node's root disk – This method enables the root disk to be mirrored, which provides a boot alternative if the root disk is corrupted or damaged. To encapsulate the root disk you need two free disk slices as well as free cylinders, preferably at the beginning or the end of the disk.

• Use local nonroot disks – This method provides an alternative to encapsulating the root disk. If a node's root disk is encapsulated, certain tasks you might later perform, such as upgrade the Solaris OS or perform disaster recovery procedures, could be more complicated than if the root disk is not encapsulated. To avoid this potential added complexity, you can instead initialize or encapsulate local nonroot disks for use as root disk groups.

  A root disk group that is created on local nonroot disks is local to that node, neither globally accessible nor highly available. As with the root disk, to encapsulate a nonroot disk you need two free disk slices as well as free cylinders at the beginning or the end of the disk.

See your VxVM installation documentation for more information.

SPARC: Where to Go From Here

Install VxVM by using one of the following installation methods, depending on how you intend to create the root disk group.

• If you intend to encapsulate the root disk, go to SPARC: How to Install VERITAS Volume Manager Software and Encapsulate the Root Disk.

• If you intend to create the root disk group on local nonroot disks, go to SPARC: How to Install VERITAS Volume Manager Software Only.