VERITAS Volume Manager 3.5 Administrator's Guide (September 2002)

Reorganizing the Contents of Disk Groups

126 VERITAS Volume Manager Administrator’s Guide

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 dg1 to rootdg:

# vxdg listmove dg1 rootdg vol1

disk01 c0t1d0 disk05 c1t96d0 vol1 vol1-01 vol1-02 disk01-01

disk05-01

However, the following command produces an error because only part of the volume

vol1 is conﬁgured on disk01:

# vxdg listmove dg1 rootdg disk01

vxvm:vxdg: ERROR: vxdg listmove dg1 rootdg failed

vxvm:vxdg: ERROR: disk05 : Disk not moving, but subdisks on it are

Specifying the -o expand option ensures that the list of objects encompasses other disks

(in this case, disk05) that contain subdisks from vol1.

# vxdg -o expand listmove dg1 rootdg disk01

disk01 c0t1d0 disk05 c1t96d0 vol1 vol1-01 vol1-02 disk01-01

disk05-01

Considerations for Placing DCO Plexes

If you use the vxassist command or the VERITAS Enterprise Administrator (VEA) to

create a volume, or to enable Persistent FastResync on a volume, the DCO plexes are

automaticallyplaced onthesame disks asthedata plexesofthe parent volume. Whenyou

move the parent volume (such as a snapshot volume) to a different disk group, this

ensures that the DCO volume automatically accompanies 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. Use the vxprint command on a volume to examine the conﬁguration

of its associated DCO volume.

“Examples of Disk Groups That Can and Cannot be Split” on page 127 illustrates some

instances in which it is not be possible to split a disk group because of the location of the

DCO plexes.

For more information about relocating DCO plexes, see “Specifying Storage for DCO

Plexes” on page 196.