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

28 Maintaining your system
Disk tasks
■ AIX coexistence label
■ HP-UX coexistence or VxVM ID block
There are also backup copies of each. If any of the primary labels become
corrupted, VxVM will not bring the disk online and user intervention is
required.
If two labels are intact, the disk is still recognized as a cdsdisk (though in the
error state) and
vxdisk flush can be used to restore the CDS disk labels from
their backup copies.
Primary labels are at sectors 0, 7, and 16; and a normal flush will not flush
sectors 7 and 16. Also, the private area is not updated as the disk is not in a disk
group. There is no means of finding a “good” private region to flush from. In this
case, it is possible to restore the CDS disk labels from the existing backups on
disk using the flush operation.
If a corruption happened after the labels were read and the disk is still online
and part of a disk group, then a flush operation will also flush the private region.
Warning: Caution and knowledge must be employed because the damage could
involve more than the CDS disk labels. If the damage is constrained to the first
128K, the disk flush would fix it. This could happen if another system on the
fabric wrote a disk label to a disk that was actually a CDS disk in some disk
group.
To rewrite the CDS ID information on a specific disk
◆ Type the following command:
# vxdisk flush disk_access_name
This rewrites all labels except sectors 7 and 16
To rewrite all the disks in a CDS disk group
◆ Type the following command:
# vxdg flush diskgroup
This rewrites all labels except sectors 7 and 16
To forcibly rewrite the AIX coexistence label in sector 7 and the HP-UX
coexistence label or VxVM ID block in sector 16
◆ Type the following command:
# vxdisk -f flush disk_access_name
This command rewrites all labels if there exists a valid VxVM ID block that
points to a valid private region. The
-f option is required to rewrite sectors