VERITAS Volume Manager 3.5 User's Guide - VERITAS Enterprise Administrator (June 2002)

Using the Volume Snapshot Feature

102 VERITAS Volume Manager User’s Guide - VEA

After the snap mirror is synchronized with the volume, it can be used as a snapshot

mirror. The synchronization process can take a while, but it does not interfere with use of

the volume. If the Snap Start process fails, the snapshot mirror is removed and its space is

released. After the mirror is synchronized, it continues to be updated until it is detached.

Note To create a snapshot mirror on a dynamic volume, you must have an empty

dynamic disk in the dynamic disk group of that volume.

▼ To create a snapshot mirror, do the following:

1. Right-click on the volume that you want to take a snapshot of.

A context menu is displayed.

2. Select Snap > Snap Start.

A new snapshot mirror is attached to the volume.

The new mirror is added to the Mirrors tab for the volume. The mirror is identiﬁed as

a Snapshot plex and is identiﬁed with the Snapshot icon. After the mirror is

synchronized with the volume, its status becomes Snap Ready.

The DCO (disk change object) volume is created to track the regions on a volume that

are changed while a mirror is detached. The DCO volume is not included in the tree

view of the Volume Manager GUI. To view the DCO volume, you must use the Disk

View. To access the Disk View, click the Disk View tab in the right pane or select Disk

View from a disk’s context menu.

Note The Break Mirror and Remove Mirror commands do not work with the snapshot

mirror.

Creating the New Volume

Snap Shot detaches the snapshot mirror and creates a new volume that is associated with

that mirror. This process takes a relatively short time, typically less than a minute, during

which users can be requested to not access the original volume. After the snapshot

volume is detached, it can be used for backup or other purposes.

To take a snapshot, do the following:

1. Right-click on the volume with the snapshot mirror.

A context menu is displayed.

2. Select Snap > Snap Shot.