Unmount NFS filesystem after IP change?

[Jorge Fabregas]

Hello everyone,

We have around 6 servers for a specific project. The other days we changed the ip for each one of the servers and we have a couple of NFS shares between them. Now, I need to fix a couple of entrees in /etc/fstab (in all servers) in order to change the reference for the NFS shares. Unfortunately the reference for the NFS servers was created using the ip (instead of hostnames) so right now...I hacve a couple of shares that are inaccesible because the NFS subsystem is still attached to the old IP's (inaccesible now).

If I try to unmount the partition ...it will stay there ..I'll get no response (I Have to open a new shell....)

I tried stopping all NFS processess...and still I'm unable to unmount. I tried fuser /my_nfs_share and it stays there. I have two or three fuser processes that I'm unable to kill (either with SIGTERM or SIGKILL).

So, my NFS subystems is still thinking on the old ip's and I have no way to unmount in order to remount again (with correct ip).

My problem is: I plan to restart server (the Windows solution :) but I'm at a remote location... My main worry is that when doing shutdown...when doing the unmount part...I'm worry that it will stay there (Unmounting...) and therefore the server won't be able to reboot properly...

Any ideas on what is the best way to proceed on this?

Thanks!
Jorge

[Dave Olker · Accepted solution]

Hello Jorge,

I've written a technical paper about this exact topic and it's available on docs.hp.com:

http://docs.hp.com/en/3929/ForciblyUnmountingNFSFilesystems.pdf

There are many different strategies you can try to resolve this problem without rebooting the NFS clients.

However, if the clients happen to be running HP-UX 11i v2 then there's an even easier solution - "umount -f".

We added a -f option to the umount command in 11.23 (11i v2) that forces the NFS client to unmount the filesystem regardless of the current state. This is designed to be used in exactly this scenario - when something happens that causes the client filesystems to be unresponsive to normal unmount requests.

So, if you're running 11i v2 on the clients, use the umount -f command. If not, get a copy of the technical paper and try some of the recommendations in it.

Hope this helps,

Dave

[Dineshkumar]

Jorge

Please refer below docs

http://www.docs.hp.com/en/3929/ForciblyUnmountingNFSFilesystems.pdf

Dinesh

[Jorge Fabregas]

Thanks for this wonderful whitepaper. Exactly what I needed!

Jorge