VERITAS Volume Manager 3.5 Administrator's Guide (September 2002)

Chapter 11, Configuring Off-Host Processing
Implementing Off-Host Processing Solutions
273
Disk Group Split and Join
Note You may need an additional license to use this feature.
A volume, such as a snapshot volume, can be split off into a separate disk group and
deported. It is then ready for importing on another host that is dedicated to off-host
processing. This host need not be a member of a cluster but must have access to the disks.
At a later stage, the disk group canbe deported, re-imported, and joined with the original
disk group or with a different disk group.
For more information, see “Reorganizing the Contents of Disk Groups” on page 121.
Implementing Off-Host Processing Solutions
As shown in“ExampleImplementation ofOff-HostProcessing” on page 273,by accessing
snapshot volumes from a lightly loaded host (shown here as the OHP host), CPU- and
I/O-intensive operations for online backup and decision support do not degrade the
performance of the primary host that is performing the main production activity (such as
running a database). Also, if you place the snapshot volumes on disks that are attached to
different host controllers than the disks in the primary volumes, it is possible to avoid
contending with the primary host for I/O resources.
Example Implementation of Off-Host Processing
Disks containing primary
volumes used to hold
production databases or
file systems
Disks containing snapshot
volumes used to
implement off-host
processing solutions
SCSI or Fibre
Channel
Connectivity
OHP Host
Primary Host