VERITAS Storage Foundation 4.1 Cross-Platform Data Sharing Administrator's Guide

Chapter 3, Maintaining Your System

Disk Group Tasks

Changing the Alignment of a Non-CDS Disk Group

Use the alignment attribute (align) with the vxdg set command to change the alignment value

of a version 110 disk group to 1 or to 8KB, as shown here:

# vxdg -g diskgroup set align=1

# vxdg -g diskgroup set align=8k

Note For a CDS disk group, alignment can only take a value of 8k. Attempts to set the

alignment of a CDS disk group to 1 fail unless you first change it to a non-CDS disk group.

Increasing the alignment may require vxcdsconvert to be run to change the layout of the

objects in the disk group.

To display the current alignment value, use the vxprint command as described in

“Displaying the Disk Group Alignment” on page 31.

The operation to increase the alignment to 8K fails if objects exist in the disk group that do not

conform to the new alignment restrictions. In that case, use the vxcdsconvert alignment

command to change the layout of the objects as described in “Converting a Non-CDS Disk Group

to a CDS Disk Group” on page 15:

# vxcdsconvert -g diskgroup [-A] [-d defaults_file] \

[-o novolstop] alignment [attribute=value] ...

This command increases the alignment value of a disk group and its objects to 8K, without

converting the disks.

The sequence 8K -> 1 -> 8K is possible only using vxdg set as long as the configuration does not

change after the 8K -> 1 transition.