Veritas FlashSnap Point-In-Time Copy Solutions 5.0 AdministratorÆs Guide, HP-UX 11i v3, First Edition, May 2008

15Point-in-time copy solutions
Implementing off-host point-in-time copy solutions
Implementing off-host point-in-time copy solutions
Figure 1-3 illustrates that, 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 are prevented from degrading 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 host controllers other than those for the disks in the primary
volumes, it is possible to avoid contending with the primary host for I/O
resources. To implement this, paths 1 and 2 shown in the following figures
should be connected to different controllers.
Figure 1-3 Example implementation of an off-host point-in-time copy solution
Figure 1-4 shows an example of how you might achieve such connectivity using
Fibre Channel technology with 4 Fibre Channel controllers in the primary host.
This layout uses redundant-loop access to deal with the potential failure of any
single component in the path between a system and a disk array.
Note: On some operating systems, controller names may differ from what is
shown here.
Network
Disks containing primary
volumes used to hold
production databases or file
systems
Disks containing snapshot
volumes
SCSI or Fibre Channel
connectivity
OHP host
Primary Host
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