HP-UX System Administrator's Guide: Logical Volume Management (762803-001, March 2014)

If the disk is hot-swappable, replace it.
If the disk is not hot-swappable, shut down the system, turn off the power, and replace the
disk. Reboot the system.
4. Notify the mass storage subsystem that the disk has been replaced.
If the system was not rebooted to replace the failed disk, then run scsimgr before using the
new disk as a replacement for the old disk. For example:
# scsimgr replace_wwid –D /dev/rdisk/disk14
This command allows the storage subsystem to replace the old disk’s LUN World-Wide-Identifier
(WWID) with the new disk’s LUN WWID. The storage subsystem creates a new LUN instance
and new device special files for the replacement disk.
5. Determine the new LUN instance number for the replacement disk.
For example:
# ioscan –m lun
Class I Lun H/W Path Driver S/W State H/W Type Health Description
========================================================================
disk 14 64000/0xfa00/0x0 esdisk NO_HW DEVICE offline HP MSA Vol
/dev/disk/disk14 /dev/rdisk/disk14
...
disk 28 64000/0xfa00/0x1c esdisk CLAIMED DEVICE online HP MSA Vol
0/1/1/1.0x3.0x0
/dev/disk/disk28 /dev/rdisk/disk28
In this example, LUN instance 28 was created for the new disk, with LUN hardware path
64000/0xfa00/0x1c, device special files /dev/disk/disk28 and /dev/rdisk/disk28,
at the same lunpath hardware path as the old disk, 0/1/1/1.0x3.0x0. The old LUN instance
14 for the old disk now has no lunpath associated with it.
NOTE: If the system was rebooted to replace the failed disk, then ioscan –m lun does
not display the old disk.
6. Assign the old instance number to the replacement disk.
For example:
# io_redirect_dsf -d /dev/disk/disk14 -n /dev/disk/disk28
This assigns the old LUN instance number (14) to the replacement disk. In addition, the device
special files for the new disk are renamed to be consistent with the old LUN instance number.
The following ioscan –m lun output shows the result:
# ioscan –m lun /dev/disk/disk14
Class I Lun H/W Path Driver S/W State H/W Type Health Description
========================================================================
disk 14 64000/0xfa00/0x1c esdisk CLAIMED DEVICE online HP MSA Vol
0/1/1/1.0x3.0x0
/dev/disk/disk14 /dev/rdisk/disk14
The LUN representation of the old disk with LUN hardware path 64000/0xfa00/0x0 was
removed. The LUN representation of the new disk with LUN hardware path
64000/0xfa00/0x1c was reassigned from LUN instance 28 to LUN instance 14 and its
device special files were renamed as /dev/disk/disk14 and /dev/rdisk/disk14.
7. Restore LVM configuration information to the new disk.
For example:
# vgcfgrestore -n /dev/vgnn /dev/rdisk/disk14
138 Troubleshooting LVM