HP Veritas Volume Manager 5.0 -UX 11i v3 manual Handling disks with duplicated identifiers

Creating and administering disk groups

Handling disks with duplicated identifiers

Enable access to (import) a disk group

Menu: VolumeManager/Disk/EnableDiskGroup

Use this operation to enable access to a

disk group. This can be used as the final part of moving a disk group from one system to another. The first part of moving a disk group is to use the “Remove access to (deport) a disk group” operation on the original host.

A disk group can be imported from another host that failed without first deporting the disk group. Be sure that all disks in the disk group are moved between hosts.

If two hosts share a SCSI bus, be very careful to ensure that the other host really has failed or has deported the disk group.

If two active hosts import a disk group at the same time, the disk group will be corrupted and will become unusable.

175

Select disk group to import [<group>,list,q,?] (default: list)

newdg

Once the import is complete, the vxdiskadm utility displays the following success message:

VxVM INFO V-5-2-374 The import of newdg was successful.

4At the following prompt, indicate whether you want to import another disk group (y) or return to the vxdiskadm main menu (n):

Select another disk group? [y,n,q,?] (default: n)

Alternatively, you can use the vxdg command to import a disk group:

#vxdg import diskgroup

Handling disks with duplicated identifiers

Advanced disk arrays provide hardware tools that you can use to create clones of existing disks outside the control of VxVM. For example, these disks may have been created as hardware snapshots or mirrors of existing disks in a disk group. As a result, the VxVM private region is also duplicated on the cloned disk. When the disk group containing the original disk is subsequently imported, VxVM detects multiple disks that have the same disk identifier that is defined in the private region. In releases prior to 5.0, if VxVM could not determine which disk was the original, it would not import such disks into the disk group. The duplicated disks would have to be re-initialized before they could be imported.

From release 5.0, a unique disk identifier (UDID) is added to the disk’s private region when the disk is initialized or when the disk is imported into a disk group (if this identifier does not already exist). Whenever a disk is brought online, the current UDID value that is known to the Device Discovery Layer (DDL) is