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Listing objects potentially affected by a move

To display the VxVM objects that would be moved for a specified list of objects, use the following command:

# vxdg [-o expand] listmove sourcedg targetdg object ...

The following example lists the objects that would be affected by moving volume vol1 from disk group mydg to newdg:

# vxdg listmove mydg newdg vol1

mydg01 sda mydg05 sde vol1 vol1-01 vol1-02 mydg01-01 mydg05-01

However, the following command produces an error because only a part of the volume vol1 is configured on the disk mydg01:

# vxdg listmove mydg newdg mydg01

VxVM vxdg ERROR V-5-2-4597 vxdg listmove mydg newdg failed

VxVM vxdg ERROR V-5-2-3091 mydg05 : Disk not moving, but subdisks on it are

Specifying the -o expand option, as shown below, ensures that the list of objects to be moved includes the other disks (in this case, mydg05) that are configured in vol1:

# vxdg -o expand listmove mydg newdg mydg01

mydg01 sda mydg05 sde vol1 vol1-01 vol1-02 mydg01-01 mydg05-01

Moving DCO volumes between disk groups

When you move the parent volume (such as a snapshot volume) to a different disk group, its DCO volume must accompany it. If you use the vxassist addlog, vxmake or vxdco commands to set up a DCO for a volume, you must ensure that the disks that contain the plexes of the DCO volume accompany their parent volume during the move. You can use the vxprint command on a volume to examine the configuration of its associated DCO volume.

If you use the vxassist command or the Veritas Enterprise Administrator (VEA) to create both a volume and its DCO, or the vxsnap prepare command to add a DCO to a volume, the DCO plexes are automatically placed on different disks from the data plexes of the parent volume. In previous releases, version 0 DCO plexes were placed on the same disks as the data plexes for convenience when performing disk group split and move operations. As version 20 DCOs support dirty region logging (DRL) in addition to Persistent FastResync, it is preferable for the DCO plexes to be separated from the data plexes. This improves the performance of I/O from/to the volume, and provides resilience for the DRL logs.

Examples of disk groups that can and cannot be split shows some instances in which it is not be possible to split a disk group because of the location of the DCO plexes on the disks of the disk group.

See "Specifying storage for version 0 DCO plexes" on page 362.

See "Specifying storage for version 20 DCO plexes" on page 285.

See "FastResync" on page 66.

See "Volume snapshots" on page 62.

See "Administering volume snapshots" on page 311.

Examples of disk groups that can and cannot be split

Examples of disk groups that can and cannot be split

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