Over mounted mount point

[Luke Bell]

Hi

I have a problem on one of my hpux 11.00 64 bit machines.

We had to power a box off when it came up it had a disk error the disks were replaced and we thought everything was ok.

however weve noticed that the filesystem mounts arnt working correctly.

we have two mount points

/dev/vg01/lvinstall
7168000 323504 6416755 5% /sapdb/LCA/install
/dev/vg01/lvsapdb 7168000 323504 6416755 5% /sapdb

which you can see are the same size in fact there is only one logicla volume that has been mounted to both mount points.

go to

/sapdb> bdf .
Filesystem kbytes used avail %used Mounted on
/dev/vg01/lvinstall
7168000 323504 6416755 5% /sapdb/LCA/install

go to

/sapdb/LCA/install> bdf .
Filesystem kbytes used avail %used Mounted on
/dev/vg01/lvinstall
7168000 323504 6416755 5% /sapdb/LCA/install

as you can see the /sapdb mount point isnt there.

however all the data from sapdb is visable but all the data in /sapdb/LCA/install is not visable.

The lvmtab looks like this(in this order):

/dev/vg01/lvsapdb /sapdb vxfs rw,suid,largefiles,delaylog,datainlog 0 2
/dev/vg01/lvinstall /sapdb/LCA/install vxfs rw,suid,largefiles,delaylog,datainlog 0 2

how do i fix this is it just umount the lvols and then remount them in the correct order or is there likely to be a much bigger problem.

Unfortunalty i dont know what the engineer did. so whats likely to cause this?

Cheers

Luke

[Patrick Wallek]

It looks like may /sapdb/LCA/install got mounted before /sapdb somehow.

Try this:

# umount /sapdb/LCA/isntall
# umount /sapdb

# mount /sapdb
# mount /sapdb/LCA/isntall

Now do a bdf and see what it shows.

[Steven E. Protter]

On the surface, it looks like two mount points with exactly the same size and use.

Which would seem unlikely.

Still it looks like there are two logical volumes and two mount points.

In this situation i would:

shut down the apps if there are any, back up the data if you care.

umount /sapdb
umount /sapdb/LCA/install

then
mount -a

Something I don't do but know is okay is mount filesystems on subdirectories. It confuses my pea brain molecules.

I suppose this could be caused if the disk the logical volume /dev/vg01lvaapdb or /sev/vg01/lvinstall was involved in the failure, wasn't there at mount time.

Strange things happen when disks fail.

A little story that might provide insite.

One day at boot /var failed to mount. Operations missed it. log files when out and wrote 50 MB to what it thought was var, but was really root.

Then we booted again because we realized /var was not mounted.

This time /var mounted.

There was 50 MB of data in use on the rootfs, but hidden from the command prompt, because there was a filesystem mounted on /var now.

No files in the rootfs under /var are visible when /var is mounted. Same goes for any filesystem.

A variation of that scenario could have occurred here.

I'd get a backup and boot the box as soon as possible. I'd also run lvdisplay on each logical volume on the system and look for irregularities.

SEP

[Luke Bell]

Hi patrick

Unfortunatly I am not in a position to be able to unmount fs until the weekend, thankfully the install dir has no useful info in it.

I figure unmounting the fs and mounting again should resolve this, but as this is a critical system if i mess up i wont be coming in on monday, so i want to make sure that iam not missing anything really.

cheers

[Luke Bell]

so steven are you saying that when i mount /dev/vg01/lvsapdb on /sapdb any new data written to it when it was mounted as /sapbd/LCA/install will be lost? and would need to be restored?

[V. Nyga]

Hi Luke,

you should be able to unmount /sapdb/LCA/install as you said you don't need it in production.
Then you could check what's in /sapdb/LCA/install from the other mount point. If it's empty it could be that you mount an empty dir over a existing dir and you see nothing.
Umount and mount /dev/vg01/lvinstall
manuelly, then you should see the contents.

Volkmar