topic Re: not able umount filesystem in Operating System - HP-UX

not able umount filesystem

himacs — Wed, 22 May 2013 09:52:45 GMT

Hi Admins,

I am facing strange issue here.

Server is B.11.31 and 3PAR storage.

Our backup policy is as follows.

We have script which creates snapshots of base volumes and mounts the same in
backup media server.

The same script also removes already mounted snapshots in backup media server
and creates latest one.

The problem here is script not able to unmount the one particular snapshot from OS level,
but removes the lun from storage side forcefully.This will create abnormal in OS,because
ioscan of disk show NO_HW for that particular disk.To solve this we have to reboot(pc -off)
the server.

I have tried with fuser,lsof with filesystem which shows device busy when umount command run.
But shows no process list.And every time same filesystem fails.

Tried 'vxumount -o force /mnt ' , but ended with no license message.

Please let me know any command similar to fuser and lsof,which lists any process is active.

Thanks

himacs

Re: not able umount filesystem

Dennis Handly — Wed, 22 May 2013 10:42:41 GMT

>Please let me know any command similar to fuser and lsof

lsof is the right tool. Perhaps glance?

Note: If you are exporting that filesystem, it will be busy in the kernel and won't be able to unmount AND lsof may not find any processes using it.

Re: not able umount filesystem

himacs — Wed, 22 May 2013 11:52:58 GMT

Hi Dennis,

Thanks for the response.

All the other sanpshots i can unmount manually using umount command.

Regards

himacs

Re: not able umount filesystem

Steve Post — Wed, 22 May 2013 12:39:05 GMT

I had a similar problem. Check out NFS.

Try unshare /yourmountpoint

And look in file /etc/dfs/dfstab.

Unknown to me that because some year I might NFS mount a filesystem, HP would never let me unmount it until it was no longer shareable by other hosts.

Re: not able umount filesystem

himacs — Wed, 22 May 2013 13:06:34 GMT

Hi Steve,

Thanks for the reply.This is not NFS mountpoint.

mountpoint is a snapshot of base volume,which mounted on backup media server.We can list contents of the filesystem but not able to umount.No help from lsof and fuser.

Regards

himacs

Re: not able umount filesystem

Steve Post — Wed, 22 May 2013 14:42:35 GMT

Well I have a caveman-ish answer.

I used this to discover that NFS is using my filesystem but not reporting it.

Shutdown the box. Bring it up in single user mode. Slowly run through the rc jobs in order ls -l /sbin/rc*.d/S* to see them all.

Eventually you will get to the spot where the filesystem is mounted.

Try unmounting it.

It can unmount? ok. remount then do the next start command.

Try unmounting it.

It can unmount? ok...repeat until you get to the spot where you cannot unmount.

Look at THAT rc job.

This is annoying and painful. And it worked for me.