NFS4: ssh + unlink(~/.Xauthority) delays

[Sven Geggus <lists@fuchsschwanzdomain.de>]

Hello,

I'm about to setup a Linux based fileserver for home directories and a
couple of Linux clients with kerberos and NFS4 (no NFS3 for security
reasons).

The whole stuff is currently based on debian stable (with a backported
current NFS userland 1.2.5) and a recent vanilla kernel (3.5.2).

So far I have the NFS4 Server up and running as well as a couple of clients
with NFS4+autofs mounted home directories.

All this stuff mostly works now, but unfortunately I ran into some strange
bahaviour now.

When I ssh from one machine to another the system hangs (a delay of up to 60
seconds) while running xauth.

Replacing xauth by a wrapper script I have been able to trace this behaviour
to a hang of an unlink("/home/<user>/.Xauthority") system call.

So the question is what cases hangs in NFS4 based Linux systems in general
an in this particular case?

Any hint on how to debug this?

Sven

-- 
"C Is Quirky, Flawed, And An Enormous Success."
(Dennis M. Ritchie)

/me is giggls@ircnet, http://sven.gegg.us/ on the Web