HP SAN Virtualization Services Platform - Manual (Page 281)

Working with user PiTs
A user PiT is a mirror PiT, the creation of which is triggered by a user, which is copied to the
destinations of all tasks running on an async mirror group. User PiTs enable you to save a snapshot
image of the data on a virtual disk at the exact time you need. For example, if you need to transfer
host production from a source virtual disk to a mirror of the virtual disk, you can stop the application,
unmount the virtual disk, create a user PiT, and then wait until the user PiT is copied to the destination.
You are now assured that all recent modifications have been copied to the destination before you
split the task and assign the host permission to access the destination virtual disk.
Another example of utilizing User PiTs is for backup purposes. The objective is to get a consistent disk
image from which applications that use databases can quickly recover. User PiTs allow you to
synchronize the application state with PiT creation. You can place the application in backup mode,
trigger a PiT creation using the Mirror User PiT feature and then release the application to normal
operation once the PiT is complete. You can then use the user PiT that was created for backup by
creating a snapshot and mounting it to backup server.
Creating user PiTs
To create a user PiT:
1. Right-click the async mirror group on which you want to create a user PiT.
2. Select Manage > Create User PiT. The Create User PiT wizard opens to the Enter PiT parameters
screen.
3. In the PiT name field, enter a name for the PiT. This will be the PiT name only on the source
domain of the group. When a user PiT is copied to task destinations, the mirror service assigns
it a new name, which is automatically generated from the destination virtual disk name
concatenated by the letters “UP,” which indicate a user PiT, and a unique time stamp number
that was assigned to the PiT at the time of creation by the source domain.
4. In the Comment field, enter any text you want.
5. Click Next. A confirmation screen appears.
6. Click Finish. The PiT is created and the group’s tasks start copying the PiT to their destinations.
The PiT is displayed in the Source Domain’s PiTs tab for the group, and you can track the life
cycle of the PiT in the Source & Destination PiTs tab. For more information, see
“
Async mirror group information--Source Domain's PiT tab ” on page 273.
Releasing user PiTs
The mirror service deletes PiTs whenever necessary on the source and on each destination to maintain
the configured limits on the number of PiTs. Standard mirror PiTs are deleted before user PiTs. When
you release user PiTs, the user PiTs lose their special status and are handled by the mirror service as
if they were standard mirror PiTs. You can release all user PiTs on a task’s destination, and you can
release all user PiTs on a group’s source.
To release user PiTs from an async mirror task destination:
1. Click an async mirror group.
2. Select the Async Mirror Task tab.
3. Right-click the task.
4. Select Manage > Release destination User PiTs. A confirmation screen appears.
5. Click Finish. The user PiTs are now handled as standard mirror PiTs.
HP StorageWorks SAN Virtualization Services Platform Manager user guide 281