NFSv4 client hangs during shutdown when server is gone

We’re trying out a UPS shutdown scenario – both NFS client and NFS server get the shutdown command at the same time. The NFS server goes down first, so when the client get to the autofs shutdown step, there is no server, and as a result hangs:

unmounting /path (force)

wait 90 seconds

/path still busy…unmounting lazy

And stays there for hours.

This is under autofs, and the path is mounted -fstype=nfs4,timeo=300,nolock,hard,intr

The manpage for nfs(5) implies “hard” will result in retries under the retrans=n heading. Is this correct? I tried “soft” already and got similar issues.

–John