On Wed, Jun 18, 2008 at 9:36 AM, Jan Schulze
<[log in to unmask]> wrote:
> Hi all,
>
> I recently upgraded a number of NFS clients from SL 4.2 to SL 5.1. The
> NFS server is still running SL 4.2. Clients are acting very slow, e.g.
>
> - after SSH authentication, it takes about 5 sec. for the console prompt
>  to appear
> - every 'ls' is slow
> - compiling stuff is terribly slow
>
> It seems to have something to do with NFS - I'm having some NFS-mounted
> directories in my $PATH (TC shell). When I throw them out, everything is
> working as expected (e.g. compiling gcc was ~9 times faster). Please
> note, that the same $PATH does not noticeably slow things down on the
> old 4.2 systems.
>
> I did comparisons compiling gcc on the old and new systems while running
> tcpdump. I found, that the new systems performed a lot more NFS lookups
> (by factor ~4). Everything else seemed normal.
>
> File transfer to the NFS server is OK, no speed problems here. Tcpdump,
> however shows a lot of lines like this one, when copying files:
>  18:19:56.571906 IP bsnode02.0 > morphin.nfs: 1448 null
>
> Load on the NFS server is much higher than before. I'm a little bit at a
> loss - how could I debug these issues further?
>
>
> Regards,
> Jan

This is a known bug.  Please see:

http://bugs.centos.org/view.php?id=2635

It was fixed in 5.2.

Akemi