[CentOS] NFS lockups

Sat Oct 3 13:56:14 UTC 2009
Mike Yates <mike.yates at hawkgrove.co.uk>

I thought this had been fixed with newer kernels?
We have an old Maxtor Snap Server, an 80 GB NAS unit, containing some of our archives.
Both of our CentOS servers have it permanently mounted by NFS for convenient access.
This weekend, I discovered remotely that, although all systems except the VRTSralus remote agents for Veritas (now Symantec) Backup Exec were working just fine, both servers would freeze a shell solid on starting to run "lsof" or half way through a "df". However, "mount" ran OK and showed the next item in the "df" should have been the Snap Server NFS mount. I pinged it and it did not respond - I'll let you know Monday what is up. "umount -f"  showed "Device busy" but "umount -l" worked just fine and "df" "lsof" and "VRTSralus" all work OK now. BTW the Veritas does not access the Snap Server, though the weekly cron-job to tar-ball the Snap Server at 02:00 Saturday did not email me at all, though it is shown in /var/log/cron.

Does anyone know of a method to make NFS mounts auto un-mount if the remote server disappears?


Mike Yates    MBCS CITP (ISSG)
IT Support Engineer

Hawkgrove Ltd  -  Software Systems Design
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