CDS disks have the following labels:
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.
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
To rewrite all the disks in a CDS disk group
To forcibly rewrite the AIX coexistence label in sector 7 and the HP-UX coexistence label or VxVM ID block in sector 16
# 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 7 and 16 when a disk is taken offline due to label corruption (possibly by a Windows system on the same fabric).