For information about the purpose and function of device groups, see Devices in Sun Cluster Overview for Solaris OS and Device Groups in Sun Cluster Concepts Guide for Solaris OS.
Add this planning information to the Device Group Configurations Worksheet.
Consider the following points when you plan device groups.
Failover – You can configure multihost disks and properly configured volume-manager devices as failover devices. Proper configuration of a volume-manager device includes multihost disks and correct setup of the volume manager itself. This configuration ensures that multiple nodes can host the exported device. You cannot configure tape drives, CD-ROMs or DVD-ROMs, or single-ported devices as failover devices.
Mirroring – You must mirror the disks to protect the data from disk failure. See Mirroring Guidelines for additional guidelines. See Configuring Solaris Volume Manager Software or Installing and Configuring VxVM Software and your volume-manager documentation for instructions about mirroring.