NFSv4 mount fails on Sun Solaris 10 after reboot of client

[Ulrich Gemkow <ulrich.gemkow@ikr.uni-stuttgart.de>]

Hello,

we have a weired problem with Linux NFSv4.0 Server (Vanilla
Kernel 4.1.6) and a Sun Solaris 10 client (all patches applied):

When mounting a share on the Solaris client and then rebooting
the client without unmounting the share first, after the reboot
every attempt to mount the share again gives an I/O error on
the client and the mount fails.

After a long time (serveral hours) the v4 mount suddenly works
again.

Mounting a share with vers=2 works always even in times when
the v4 mount fails.

So it seems the Linux NFSv4 server holds a state for the client
which prevents the re-mounting of the share and gives the
I/O-error on the client.

We use NFSv4 without idmapd.

Is there any tip how to debug or solve this?

Thank you and best regards

-Ulrich

-- 
|-----------------------------------------------------------------------
| Ulrich Gemkow
| University of Stuttgart, Germany
| Institute of Communication Networks and Computer Engineering (IKR)
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