VERITAS Volume Manager 3.5 User's Guide - VERITAS Enterprise Administrator (June 2002)

General Troubleshooting
156 VERITAS Volume Manager User’s Guide - VEA
Volume State: Degraded
The RAID-5 volume is in a degraded mode. This usually occurs when one or more
subdisks are unavailable and read requests require data reconstruction. An underlying
disk may have failed completely or there may be I/O errors on part of a disk.
Alternatively, an underlying disk may be disconnected.
❖ Make sure that the physical disks are turned on, plugged in, and attached to the
computer. Repairany disk, controller, or cable problems. Scan the disks onthe system
(Rescan) to make sure that VxVM recognizes any newly attached hardware.
To return the RAID-5 volume to a healthy state, recover the volume.
❖ If there has been a partial or complete disk failure, either replace the disk or move the
affected subdisks to another disk.
Volume State: Unusable
The RAID-5 volume is unusable. This usually occurs when there is a double disk failure
(that is, when two subdisks in the same stripe or the parity and one subdisk in a stripe are
damaged or inaccessible). The underlying disks may have failed or become inaccessible.
❖ Make sure that the physical disks are turned on, plugged in, and attached to the
computer. Repairany disk, controller, or cable problems. Scan the disks onthe system
(Rescan) to ensure that VxVM recognizes any newly attached hardware.
Run the following command to reattach the disks to their disk group:
# /etc/vx/bin/vxreattach [device_name]
To return the RAID-5 volume to a healthy state, recover the volume.
❖ If two of the volume disks have failed, the RAID-5 volume data is unusable. Replace
the faileddisks andthen try to restartthe volumeby runningthe following command:
# vxvol -f start volume_name
Restore the volume from backup.
To prevent this problem in the future, enable logging for RAID-5 volumes.
General Troubleshooting
General troubleshooting includes:
◆ Client/Server Problems
◆ Configuration Changes