Comment # 9 on bug 934202 from Neil Brown

Thanks, there are extra hints in there - particularly the fact that it tries to
open with O_WRONLY|_O_CREAT|O_EXCL first.
I suspect that is where the strange O_WRONLY open comes from - it shouldn't
still be around, but somehow it is.

Can you try removing the agent-medusa file, enabling NFS debugging (rpcdebug -m
nfs -s all), start a tcpdump capture and an strace capture, and then log in (or
whatever triggered that last trace).

I want to see exactly how the Netapp responds to the O_CREAT|O_EXCL sequence
and whatever follows when it succeeds.
I'm guessing that something happens in that case which confuses the client, and
then subsequent attempts are handled badly because of that confusion.

Thanks.