Step 7: Replacing a Bad Disk (Legacy DSFs)
Follow these steps to replace a bad disk if your system is configured with only legacy DSFs.
NOTE:
LVM recommends the use of persistent device special files, because they support a greater
variety of load balancing options. For replacing a disk with persistent device special files, see
“Step 6: Replacing a Bad Disk (Persistent DSFs)” (page 129)
To replace a bad disk, follow these steps.
1.
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, disable user and LVM access to all unmirrored logical volumes.
•
First, disable user access to all unmirrored logical volumes or any mirrored logical volumes
without an available and current mirror copy. Halt any application and
umount
any file
systems using these logical volumes. This prevents the applications or file systems from
writing inconsistent data over the newly restored replacement disk.
•
After disabling user access to the unmirrored logical volumes, disable LVM access to the
disk, as follows:
# pvchange -a N pvname
The following recommendation are intended to maximize system uptime and access to the
volume group, but you can use a stronger approach if your data and system availability
requirement allows.
•
If
pvdisplay
shows “PV status” as available, halt LVM access to the disk by removing
it from the volume group.
•
If
pvdisplay
show “PV status” as unavailable, or if
pvdisplay
fails to print the status,
use
ioscan
to determine if the disk can be accessed at all. If
ioscan
reports the disk
status as
NO_HW
on all its hardware paths, you can remove the disk. If
ioscan
shows
any other status, halt LVM access to the disk by deactivaing the volume group.
2.
Replace the Faulty Disk
If the disk is hot-swappable, you can replace it without powering down the system. Otherwise,
power down the system before replacing the disk. For the hardware details on how to replace
the disk, see the hardware administrator’s guide for the system or disk array. If you powered
down the system, reboot it normally. The only exception is if you replaced a disk in the root
volume group.
•
If you replaced the disk that you normally boot from, the replacement disk does not contain
the information needed by the boot loader. If your root disk is mirrored, boot from it by
using the alternate boot path. If the root disk was not mirrored, you must reinstall or
recover your system.
•
If there are only two disks in the root volume group, the system probably fails its quorum
check as described in
“Volume Group Activation Failures” (page 111)
. It can panic early
in the boot process with the message:
panic: LVM: Configuration failure
In this situation, you must override quorum to boot successfully. Do this by interrupting
the boot process and adding the
–lq
option to the boot command.
For information on the boot process and how to select boot options, see HP-UX System
Administrator's Guide: Configuration Management.
138
Troubleshooting LVM