Filesystem spontaneously disappears

[spex]

Hello,

I recently attached new storage to an RP5470 running HP-UX 11.00 and JFS 3.3. I created four new LUNs, PVs, LVs, and mountpoints and mounted the LVs, no problem. However, over the weekend, one of the new filesystems disappeared (I'm not sure that it's accurate to say "it unmounted itself"). After mounting the filesystem again, it disappeared within minutes. But after mounting one more time, it's been fine for a few days now. Logs show no errors/messages at all.

fstab entries are of the form:
/dev/vg05/lvol4 /u04 vxfs rw,suid,largefiles 0 2

I was wondering if anyone else has experienced a similar scenario in which a filesystem spontaneously disappears. Please note that it's not feasible to upgrade this older server to 11i.

Thanks for your input.

[TwoProc]

I've seen PV's dissapear from an lvm (years back) - but we had multiple paths so we'd have to add them back.

Did this file ssytem have only one PV?

[spex]

Yes, /u04 has only one PV. But another filesystem (/u03) on the same PV was unaffected.

[John Guster]

I would check if the LUNs are assigned to this server correctly. Do ioscan -fn when it is disappeared. What is the new storage hardware? Something down the hardware path is not set correctly. Cheers.

[Geoff Wild]

Is /u04 also an auto map?

IE: in /etc/auto.direct ?

The other thing to try, back it up (if there's data there), then blow it away and re-create it.

Rgds...Geoff

[Bill Hassell]

"disappears"

When this happens, is the /u04 directory empty? What do these commands show:

bdf /u04

grep u04 /etc/mnttab

ll /dev/vg05/lvol4

If bdf reports that /u04 is part of the / filesystem then indeed the filesystem is no longer mounted. Loss of /dev/vg05 directory and device files would not cause this as these are used only when the filesystem is mounted. The vxfs code has the descriptor information in memory. Loss of connection between the computer and the disk(s) for lvol4 should result in lots of dmesg and syslog entries.

If all is normal but /u04 is empty it would seem that something has removed the entry from the mount table. I assume that /u04 is always busy with Oracle so a normal umount would not work (mount point busy). I would check up on all the patches for filesystem and mount code.