Veritas Storage Foundation Cross-Platform Data Sharing 5.0 AdministratorÆs Guide, HP-UX 11i v3, First Edition, May 2008

30 Maintaining your system
Disk group tasks
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 of a disk group, use the vxprint
command.
See “Displaying the disk group alignment” on page 36.
To change the alignment value of a disk group
◆ Type the vxdg set command:
# vxdg -g diskgroup set align={1|8k}
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:
# 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 to 1 to 8K is possible only using
vxdg set as long as the
configuration does not change after the 8K to 1 transition.
See “Converting a non-CDS disk group to a CDS disk group” on page 23.
Splitting a CDS disk group
You can use the vxdg split command to create a CDS disk group from an
existing CDS disk group. The new (target) disk group preserves the setting of the
CDS attribuet and alignment in the original (source) disk group.
To split a CDS disk group
◆ Use the vxdg split command to split CDS disk groups.
See the Veritas Volume Manager Adminstrator’s Guide.
Moving objects between CDS disk groups and non-CDS disk groups
The alignment of a source non-CDS disk group must be 8K to allow objects to be
moved to a target CDS disk group. If objects are moved from a CDS disk group to
a target non-CDS disk group with an alignment of 1, the alignment of the target
disk group remains unchanged.