Creating a snapshot group – Dell PowerVault MD3260i User Manual

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Create Consistency Group

Starting, Stopping And Resuming A Snapshot Rollback

The command line interface allows you to:

start a rollback operation from multiple snapshot images concurrently

stop a rollback operation

resume a rollback operation

When rolling back, the host will have immediate access to the new-rolled-back base virtual disk, but the existing base
virtual disk will not allow the host read-write access once the rollback is initiated.

NOTE: Create a snapshot of the base virtual disk just prior to initiating the rollback to preserve the pre-rollback
base virtual disk for recovery purposes.

When you start a rollback operation for a set of snapshot images, the content of the base virtual disk changes
immediately to match the point-in-time content of the selected snapshot image virtual disk. The base virtual disk
immediately becomes available for read/write requests after the rollback operation has successfully completed.
To start a rollback for a snapshot group named snapGroup1:
start snapImage ["snapGroup1"] rollback

You can specify a snapshot image rollback for a specific snapshot image in a snapshot group named 12345:
stop snapImage ["snapGroup1:12345"] rollback;

To stop a rollback operation for the most recent snapshot image in a snapshot group that has the name snapGroup1:
stop snapImage ["snapGroup1:newest"] rollback;

The repository virtual disk associated with the snapshot image continues to track any new changes between the base
virtual disk and the snapshot image virtual disk that occur after the rollback operation is completed.
To resume a rollback operation for the same snapshot image and snapshot group:
resume snapImage ["snapgroup1:12345"] rollback;

Creating A Snapshot Group

A snapshot group is a sequence of point-in-time images of a single associated base virtual disk. A snapshot group uses
a repository to save data for all snapshot images contained in the group. The repository is created at the same time the
snapshot group is created.
Guidelines when creating a snapshot group:

When a base virtual disk that contains a snapshot group is added to an asynchronous remote replication group,

the system automatically changes the repository full policy to automatically purge the oldest snapshot image

and sets the auto-delete limit to the maximum allowable snapshot limit for a snapshot group.

If the base virtual disk resides on a standard disk group, the repository members for any associated snapshot

group can reside on either a standard disk group or a disk pool. If a base virtual disk resides on a disk pool, all

repository members for any associated snapshot group must reside on the same disk pool as the base virtual

disk.

You cannot create a snapshot group on a failed virtual disk.

If you attempt to create a snapshot image, that snapshot image creation operation might remain in a Pending

state because of the following conditions:

– The base virtual disk that contains this snapshot image is a member of an asynchronous remote

replication group.

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