The LVMVG agent provides the hadevice utility. This utility checks the status of a disk device and resets a disk device to an available state. The utility then breaks any SCSI reservations on a disk device. Its syntax is:

# hadevice -c | -r | -b -p device_name

The five possible states of a disk device are: AVAILABLE, DEFINED AND RESERVED, DEFINED AND UNRESERVED, PERSISTENT RESERVATION, and AVAILABLE AND OPEN.

To check the state of a disk device, enter:

    # hadevice -c device_name

The following commands locate and remove ghost disks for a disk device and break any SCSI reservation on the disk device. When the -p flag follows the -b flag, it breaks any previous SCSI reservation on the device. It then obtains and retains a new reservation on the device. For SDD (vpath) disks, ghost disks are not created. Both the -b and -r flags remove any persistent reservation and clear all reservation key registration on the device. The -p flag (retain reservation) is not applicable for SDD disks.

To break any SCSI reservations on the disk device, enter:

    # hadevice -b device_name

To break any SCSI reservations on the disk device, and obtain and retain a new reservation on the device, enter:

    # hadevice -b -p device_name

To locate and remove ghost disks, reset a disk device that is in a DEFINED state and put it into an AVAILABLE state, enter:

    # hadevice -r device_name