misc/154255: NFS not responding

[Sebastian Tymków]

>Number:         154255
>Category:       misc
>Synopsis:       NFS not responding
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    freebsd-bugs
>State:          open
>Quarter:        
>Keywords:       
>Date-Required:
>Class:          sw-bug
>Submitter-Id:   current-users
>Arrival-Date:   Mon Jan 24 08:20:13 UTC 2011
>Closed-Date:
>Last-Modified:
>Originator:     Sebastian Tymków
>Release:        8.1-RELEASE
>Organization:
>Environment:
FreeBSD hostname 8.1-RELEASE FreeBSD 8.1-RELEASE #0: Sat Jan  8 22:36:12 CET 2011     usernamek at hostname:/usr/src/sys/amd64/compile/GENERIC  amd64
>Description:
NFS hangs on connection to resource on netapp device.
I get messages like this:

nfs server nfsserver:/vol/nfs_resource: not responding

When I try to reboot machine it stucks on nfs and only power cycle can help.
I tried different kernels ( STABLE, RELEASE and brach) but none of them worked. 

Below is how NFS is' mounted.

nfsserver:/vol/nfs_resource        /nfs_resource    nfs     rw,noexec,nosuid,intr,nfsv3,mntudp,rsize=8192,wsize=8192                     0 0
>How-To-Repeat:

>Fix:


>Release-Note:
>Audit-Trail:
>Unformatted: