NFS lockup when copying a "special" file

Oliver Lehmann lehmann at
Tue Sep 5 15:42:28 UTC 2006

Oliver Fromme wrote:

> Did you try any of the suggestions in my previous mail?
> E.g.:  use TCP NFS transport instead of UDP, and/or force
> NFSv2 instead of NFSv3.  You could also try lowering the
> MTU (although I think it's not the cause of the problem
> in your case, but it might be worth a try nonetheless).

I now switched to TCP NFS.

> What are your NFS mount options?  What is the size of the
> file on which the mount became stuck?  Do the contents of
> the file matter?  i.e. when you create a file of the same
> size with dd(1) that contains only zeroes, can you copy
> it to the NFS share?

Mount options are:

This time it was during playing music from nfs and scping a large
file from nfs to another system - so I can't tell this time what
exactly caused it.
At least the 1st appearence of the problems two month ago happend when
copying a file which was reproduceable. The file is still online in
that tar file: - yang.xchatlog

> A bit of tcpdump output might be helpful, too.  Please use
> the options "-vv -s1600", otherwise it's useless.

My initial mail only contained a standard tcpdump

19:18:39.582342 IP > 1472 write [|nfs]
19:18:39.582344 IP > udp
19:18:39.582346 IP > udp
19:18:39.582348 IP > udp

 Oliver Lehmann

More information about the freebsd-fs mailing list