Splitting mirrored volumes

What splitting a mirrored volume is

Splitting a mirrored volume removes the mirrored data relationship between the two plexes and creates two independent unmirrored volumes. After splitting, the new volume is in a restricted state and the original volume stays in an online state.

Note
You cannot rejoin the two new unmirrored volumes to recreate the original mirrored volume. To mirror one or both of these volumes, see Adding a plex to an existing unmirrored volume.

Why you might split a mirrored volume

You might split a mirrored volume for one of the following reasons:

You want to unmirror the mirrored volume. This is an alternative to the unmirroring procedure described in Removing and destroying a plex from a mirrored volume.
You want to move a mirrored volume to another location.
You want to modify the mirrored volume, but you want to test the modification before applying it. You can apply the modifications and test them on the split-off copy of the plex and then apply those changes back to the untouched original plex.
Note
You do not need to stop applications that are running before splitting a mirrored volume.

Splitting a mirrored volume

To split a mirrored volume into two independent unmirrored volumes, complete the following steps.

Note
Ensure that both plexes of the mirrored volume you are splitting are online and operational. See Changing the state of a plex for information about viewing the state of a plex.

Step	Action
1	Enter the following command: vol split plexname volname plexname is the name of one of the plexes in the mirrored volume. volname is the name of the new volume. Example In this example, use the following command to split plex0 from mirrored volume vol0 and name the new volume volNew: vol split vol0/plex0 volNew After splitting, there are two unmirrored volumes, vol0 and volNew.

Step

Action

Enter the following command:

vol split plexname volname

plexname is the name of one of the plexes in the mirrored volume.

volname is the name of the new volume.

Example

In this example, use the following command to split plex0 from mirrored volume vol0 and name the new volume volNew:

vol split vol0/plex0 volNew

After splitting, there are two unmirrored volumes, vol0 and volNew.

Volume structure after splitting

Before splitting, a mirrored volume has two plexes, plex0 and plex1. After splitting, the new unmirrored volume with the new name has one plex, plex0. The new unmirrored volume with the original name also has one plex, but depending on which plex you chose when splitting, the plex name can be either plex0 or plex1.

The plex name for an unmirrored volume is unimportant because the volume has only one plex. If you remirror one of these unmirrored volumes, the resulting mirrored volume plex names will always be plex0 and plex1.