HP SAN Virtualization Services Platform - Manual (Page 271)

8. Uncheck Create standard PiTs if you do not want the mirror service to create standard PiTs on
the group source element. If you uncheck Create standard PiTs, the destination VDG will only be
updated when you create a user PiT.
9. From the User PiT Copy mode dropdown box, select a user PiT copy mode. The user PiT copy
mode determines the mirror service’s copying policy when more than one user PiT is waiting to
be copied to a destination. The user PiT copy mode affects all tasks in the group. Select one of
the following:
• Copy newest PiTs—When the time comes to start a copy of a new PiT to the destination, the
mirror service copies only the newest user PiT. This means that some user PiTs may be skipped.
• Copy all PiTs—The mirror service copies all user PiTs to the destination, even if there is more
than one waiting to be copied at a time when conditions become suitable for the service to
copy.
CAUTION:
On low bandwidth IP links, it is possible to have more data to copy than the link will allow
over the PiT interval. If the Copy all PiTs option is selected, it is possible that data will back
up at the source site, resulting in older than expected data on the destination site. Best practice
is to have enough bandwidth to copy a maximum sized PiT within any one PiT interval. This
requires an understanding of data change rates and link behavior, such as error rates, and
so on.
NOTE:
User PiT Copy mode is only configurable for user PiTs. The mirror service always operates
in Copy newest PiTs mode for standard PiTs.
10. In the “Minimum creation time between two PiTs” field, enter the interval at which the mirror
service should check for conditions suitable for creating a new standard PiT. Select the time units
from the dropdown box. This will be the minimum time difference between two successive mirror
standard PiTs. Select the time units from the dropdown box.
11. In the Required destination PiTs field, enter the number of mirror PiTs that should be maintained
on each task’s destination VDG at any time.
12. In the Destination PiTs Alert field, enter the number of PiTs above the number specified in the
Required destination PiTs field to allow before triggering an alert. If the number of PiTs on each
task’s destination VDG exceeds the sum of the Required destination PiTs and the Destination Pits
alert values, an alert event is sent, if VSM Service alerts are enabled.
13. In the Comment field, enter any text you want.
14. If you right-clicked the VDG on which you want to create the group in step 1, continue with step
18. Otherwise, click Next. The Select VDG screen appears, displaying the list of available VDGs.
15. If you would like to select a VDG from a folder, navigate to the folder in the tree on the left of
the screen. The Select VDG Snapshots screen displays the list of VDGs in the selected folder.
16. Select the VDG that you want to mirror.
17. Click Add. The VDG you selected appears in the lower right area of the screen. If you want to
deselect the VDG, select it in the lower right area and click Remove.
18. Click Next. The Select destination domain screen appears, displaying the local domain and any
domains exposed to the local domain.
HP StorageWorks SAN Virtualization Services Platform Manager user guide 271