User guide

Chapter 4 Managing SAN Storage 65
Checking the Integrity of a Volume
If SAN users have trouble accessing les, use the cvfsck command to check the
integrity of a volume, its metadata, and its les.
To check a volume:
1 Open Terminal (in /Applications/Utilities/).
2 If you aren’t working at the SAN controller computer, use SSH to log in to the controller
remotely:
$ ssh user@computer
Replace user with the name of an administrator user on the controller computer and
computer with the controller’s name or IP address.
3 Run the cvfsck command-line utility (in /Library/Filesystems/Xsan/bin/) to check the
volume without making repairs:
$ sudo cvfsck -vn volume
You’ll see a warning that the journal is active; this is normal.
For more information about this command, see the cvfsck man page.
Checking RAID Devices
If a RAID array that belongs to an Xsan volume becomes damaged and unrecoverable
due to a failed disk drive or other hardware failure, the data on the volume can be lost.
To avoid this possibility:
Regularly check the state of your RAID hardware, either by using the management Â
application that came with the RAID system or by visiting the hardware to check
the state of the status lights. You might be able to set up your RAID system
management application to notify you when an array is degraded.
If an array becomes degraded, replace the failed drive immediately to avoid the Â
possibility of an additional drive failure causing the loss of the entire array. To have
this happen automatically, set up your arrays with hot spare drives.