Veritas Volume Manager 5.0 Administrator's Guide (September 2006)

265Administering volumes

Removing a mirror

When a mirror is no longer needed, you can remove it to free up disk space.

Note: The last valid plex associated with a volume cannot be removed.

To remove a mirror from a volume, use the following command:

# vxassist [-g diskgroup] remove mirror volume

Additionally, you can use storage attributes to specify the storage to be removed. For

example, to remove a mirror on disk mydg01 from volume vol01, enter:

# vxassist -g mydg remove mirror vol01 !mydg01

For more information about storage attributes, see “Creating a volume on specific disks”

on page 236.

Alternatively, use the following command to dissociate and remove a mirror from a

volume:

# vxplex [-g diskgroup] -o rm dis plex

For example, to dissociate and remove a mirror named vol01-02 from the disk group,

mydg, use the following command:

# vxplex -g mydg -o rm dis vol01-02

This command removes the mirror vol01-02 and all associated subdisks. This is

equivalent to entering the following separate commands:

# vxplex -g mydg dis vol01-02

# vxedit -g mydg -r rm vol01-02

Adding logs and maps to volumes

In Veritas Volume Manager, several types of volume logs and maps are supported:

■ FastResync Maps are used to perform quick and efficient resynchronization of

mirrors (see “FastResync” on page 66 for details). These maps are supported either in

memory (Non-Persistent FastResync), or on disk as part of a DCO volume (Persistent

FastResync). Two types of DCO volumes are supported:

■ Version 0 DCO volumes only support Persistent FastResync for the traditional

third-mirror break-off type of volume snapshot. See “Version 0 DCO volume

layout” on page 69, and “Adding a version 0 DCO and DCO volume” on

page 348 for more information.

■ Version 20 DCO volumes, introduced in VxVM 4.0, support DRL logging (see

below) and Persistent FastResync for full-sized and space-optimized instant

volume snapshots. See “Version 20 DCO volume layout” on page 69, and

“Preparing a volume for DRL and instant snapshots” on page 266 for more

information.