HP P6000 Replication Solutions Manager User Guide (T3680-96089, October 2012)

• When I perform a manual extend or shrink, I can choose to extend the virtual disk or the file
system. When I use a dynamic capacity policy, I don't have this choice. How does a extend
or shrink policy work?
When using an extend or shrink policy, the size of both the file system and the underlying
virtual disk is changed when the specified threshold is reached.
• Can I install more than one extend policy or shrink policy on the same host volume?
No. You can only install one extend policy or shrink policy on a host volume.
DC-Management best practices
• When setting a dynamic policy, observe the guidelines in Selecting the proper dynamic
capacity policy thresholds.
• You cannot extend or shrink a file system on a write-protected disk. You can extend or shrink
the underlying virtual disk on a write-protected disk. Shrinking the virtual disk in this case
would enable you recover unused capacity.
• Be sure to observe the guidelines when using DC-Management with replication. See Using
DC-Management with replication for more information.
• Ensure that you have the necessary DC-Management license installed. When using
DC-Management with HP P6000 Continuous Access, HP recommends you install a
DC-Management license on both the source and destination arrays to ensure proper operation
during failover.
• Use care when manually resizing a host volume on which you have set a policy. For more
information, see Selecting the proper dynamic capacity policy thresholds.
DC-Management examples
The following example presents one scenario for using DC-Management to manage storage
capacity.
Scenario 1
An administrator needs to create a database for the production group. The administrator does not
know how much storage to allocate, but the request is for 200 GB. The administrator decides to
allocate 100 GB initially and use DC-Management policies to resize the capacity as necessary.
An extend policy is set using a threshold of 80% and an increment value of 10 GB. When the size
of the database reaches 80 GB (80% of 100 GB), the DCM policy will trigger and incrementally
increase the size of the host volume.
The administrator also decides to set a DC-Management shrink policy to reduce the size of the
host volume. This may be useful to account for periods of activity during which the database
temporarily grows to a larger size. When the size of the database decreases to the set threshold,
the shrink policy triggers to reduce the size of the host volume.
The administrator uses the email notification feature to be alerted when either policy triggers.
144 Host volumes