Guidelines for Volume Manager software

Consider the following general guidelines when configuring your disks.

• Mirrored multihost disks - You must mirror all multihost disks across disk expansion units. See "Mirroring Multihost Disks" for guidelines on mirroring multihost disks.

• Mirrored root - Mirroring the root disk ensures high availability, but such mirroring is not required. See "Mirroring Guidelines" for guidelines on deciding whether to mirror the root disk.

• Unique naming - On any cluster node, if a local Solstice DiskSuite metadevice or VxVM volume is used as the device on which the /global/.devices/node@nodeid file system is mounted, the name of that metadevice or volume must be unique throughout the cluster.

• Node lists - To ensure high availability of a disk device group, make its node lists of potential masters and its failback policy identical to any associated resource group. Or, if a scalable resource group uses more nodes than its associated disk device group, make the scalable resource group's node list a superset of the disk device group's node list. Refer to the resource group planning information in Sun Cluster 3.0 Data Services Installation and Configuration Guide for information about node lists.

• Multiported disks - You must connect, or port, all disks used to construct a device group within the cluster to all of the nodes configured in the node list for that device group. Solstice DiskSuite software is able to automatically check for this at the time that disks are added to a diskset. However, configured VxVM disk groups do not have an association to any particular set of nodes. In addition, when you use the clustering software to register Solstice DiskSuite disksets, VxVM disk groups, or individual sets of global devices as global device groups, you can perform only limited connectivity checking.

• Hot spare disks - You can use hot spare disks to increase availability, but they are not required.

Refer to your volume manager documentation for disk layout recommendations and any additional restrictions.