NFS server fail-over - how do you do it?

[adp]

One of my big problems right now is that if our primary NFS server goes down
then everything using that NFS mount locks up. If I change to the mounted
filesystem on the client then it stalls:

# pwd
/root
# cd /nfs-mount-dir
[locks]

If I try to reboot the reboot fails as well since FreeBSD can't unmount the
filesystem!?

How do I stop this from happening?

I am using this to mount NFS filesystems:

# mount -o bg,intr,soft ...

----- Original Message -----
From: "adp" <dap99 at i-55.com>
To: <questions at freebsd.org>
Sent: Sunday, May 30, 2004 2:43 AM
Subject: NFS server fail-over - how do you do it?


> I am running a FreeBSD 4.9-REL NFS server. Once every several hours our
main
> NFS server replicates everything to a backup FreeBSD NFS server. We are
okay
> with the gap in time between replication. What we aren't sure about is how
> to automate the fail-over between the primary to the secondary NFS server.
> This is for a web cluster. Each client mounts several directories from the
> NFS server.
>
> Let's say that our primary NFS server dies and just goes away. What then?
> Are you periodically doing a mount or a file look-up of a mounted
filesystem
> to check if your NFS server died? If so are you just unmounting and
> remounting everything using the backup NFS server?
>
> Just curious how this problem is being solved.
>
>