Moving disk groups between systems

An important feature of disk groups is that they can be moved between systems. If all disks in a disk group are moved from one system to another, then the disk group can be used by the second system. You do not have to re-specify the configuration.

To move a disk group between systems

  1. Confirm that all disks in the diskgroup are visible on the target system. This may require masking and zoning changes.

  2. On the source system, stop all volumes in the disk group, then deport (disable local access to) the disk group with the following command:

    # vxdg deport diskgroup
  3. Move all the disks to the target system and perform the steps necessary (system-dependent) for the target system and VxVM to recognize the new disks.

    This can require a reboot, in which case the vxconfigd daemon is restarted and recognizes the new disks. If you do not reboot, use the command vxdctl enable to restart the vxconfigd program so VxVM also recognizes the disks.

  4. Import (enable local access to) the disk group on the target system with this command:

    # vxdg import diskgroup

    Warning:

    All disks in the disk group must be moved to the other system. If they are not moved, the import fails.

  5. By default, VxVM enables and starts any disabled volumes after the disk group is imported.

    See Setting the automatic recovery of volumes.

    If the automatic volume recovery feature is turned off, start all volumes with the following command:

    # vxrecover -g diskgroup -sb

    You can also move disks from a system that has crashed. In this case, you cannot deport the disk group from the source system. When a disk group is created or imported on a system, that system writes a lock on all disks in the disk group.

    Warning:

    The purpose of the lock is to ensure that SAN-accessed disks are not used by both systems at the same time. If two systems try to access the same disks at the same time, this must be managed using software such as the clustering functionality of VxVM. Otherwise, data and configuration information stored on the disk may be corrupted, and may become unusable.