9.
Recover any lost data.
LVM recovers all the mirrored logical volumes on the disk, and starts that recovery when the
volume group is activated.
For all the unmirrored logical volumes that you identified in
Step 2
, “Halt LVM access to the
disk,” restore the data from backup and reenable user access as follows:
•
For raw volumes, restore the full raw volume using the utility that was used to create your
backup. Then restart the application.
•
For file systems, you must re-create the file systems first. For example:
# newfs -F fstype /dev/vgnn/rlvolnn
Use the logical volume's character device file for the
newfs
command. For file systems
that had nondefault configurations, see newfs(1M) for the correct options.
After creating the file system, mount it under the mount point that it previously occupied.
Then restore the data for that file system from your full backups.
TIP:
To make the file system restoration step easier, record how they were originally
created. You can change other file system parameters, such as those used to tune file
system performance. The file system must be at least as large as before the disk failure.
Replacing a Mirrored Boot Disk
There are two additional operations you must perform when replacing a mirrored boot disk:
1.
You must initialize boot information on the replacement disk.
2.
If the replacement requires rebooting the system, and the primary boot disk is being replaced,
you must boot from the alternate boot disk.
In this example, the disk to be replaced is at lunpath hardware path 0/1/1/1.0x3.0x0, with
device special files named
/dev/disk/disk14
and
/dev/rdisk/disk14
. The system is an
HP Integrity server, so the physical volume names must specify the HP-UX partition on the boot disk
(
/dev/disk/disk14_p2
and
/dev/disk/disk14_p2
).
1.
Save the hardware paths to the disk.
Run the
ioscan
command and note the hardware paths of the failed disk as follows:
# ioscan –m lun /dev/disk/disk14
Class I Lun H/W Path Driver S/W State H/W Type Health Description
========================================================================
disk 14 64000/0xfa00/0x0 esdisk CLAIMED DEVICE offline HP MSA Vol
0/1/1/1.0x3.0x0
/dev/disk/disk14 /dev/rdisk/disk14
/dev/disk/disk14_p1 /dev/rdisk/disk14_p1
/dev/disk/disk14_p2 /dev/rdisk/disk14_p2
/dev/disk/disk14_p3 /dev/rdisk/disk14_p3
In this example, the LUN instance number is 14, the LUN hardware path is
64000/0xfa00/0x0, and the lunpath hardware path is 0/1/1/1.0x3.0x0.
When the failed disk is replaced, a new LUN instance and LUN hardware path are created.
To identify the disk after it is replaced, you must use the lunpath hardware path
(0/1/1/1.0x3.0x0).
2.
Halt LVM access to the disk.
If the disk is not hot-swappable, power off the system to replace it. By shutting down the system,
you halt LVM access to the disk, so you can skip this step.
If the disk is hot-swappable, detach the device using the
–a
option of the
pvchange
command:
# pvchange -a N /dev/disk/disk14_p2
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Troubleshooting LVM