How can I perform filesystem repair with an old NAS Enterprise module?

Old NAS Enterprise modules do not have the filesystem repair feature.  If you cannot update, we recommend you boot another Linux distribution with XFS support, such as System Rescue CD:

http://www.sysresccd.org/Main_Page

After booting, your data will appear in the /dev/mapper directory (the volume designation will look like this: vg0-lv00). You'll need to mount your volumes using the mount command - please do not mount in the /mnt directory, but rather in a custom folder you have created yourself.

Afterwards, you should be able to use tools such as xfs_check and xfs_repair to diagnose the problem.