Veritas Volume Manager 5.0 Troubleshooting Guide Guide (September 2006)

15Recovery from hardware failure

Forcibly restarting a disabled volume

If a disk failure caused a volume to be disabled, and the volume does not contain any valid

redundant plexes, you must restore the volume from a backup after replacing the failed

disk. Any volumes that are listed as Unstartable must be restarted using the

vxvol

command before restoring their contents from a backup:

# vxvol [-g diskgroup] -o bg -f start volume

The -f option forcibly restarts the volume, and the -o bg option resynchronizes its plexes

as a background task. For example, to restart the volume myvol so that it can be restored

from backup, use the following command:

# vxvol -g mydg -o bg -f start myvol

Clearing the failing flag for a disk

If I/O errors are intermittent rather than persistent, Veritas Volume Manager sets the

failing flag on a disk, rather than detaching the disk. Such errors can occur due to the

temporary removal of a cable, controller faults, a partially faulty LUN in a disk array, or a

disk with a few bad sectors or tracks.

If the hardware fault is not with the disk itself (for example, it is caused by problems with

the controller or the cable path to the disk), you can use the

vxedit command to unset the

failing flag after correcting the source of the

I/O error.

Caution: Do not unset the failing flag if the reason for the I/O errors is unknown. If the

disk hardware truly is failing, and the flag is cleared, there is a risk of data loss.

To clear the failing flag on a disk:

1Use the

vxdisk list command to find out which disks are failing:

# vxdisk list

DEVICE TYPE DISK GROUP STATUS

c1t1d0 auto:simple mydg01 mydg online

c1t1d0 auto:simple mydg02 mydg online failing

c1t1d0 auto:simple mydg03 mydg online

. . .

2Use the vxedit set command to clear the flag for each disk that is marked as

failing (in this example, mydg02):

# vxedit set failing=off mydg02

3Use the vxdisk list command to verify that the failing flag has been cleared:

# vxdisk list

DEVICE TYPE DISK GROUP STATUS

c1t1d0 auto:simple mydg01 mydg online