NFS 75 second stall

[alan bryan]

--- On Thu, 7/1/10, Jeremy Chadwick <freebsd at jdc.parodius.com> wrote:

> From: Jeremy Chadwick <freebsd at jdc.parodius.com>
> Subject: Re: NFS 75 second stall
> To: "alan bryan" <alan.bryan at yahoo.com>
> Cc: freebsd-stable at freebsd.org
> Date: Thursday, July 1, 2010, 1:53 PM
> On Thu, Jul 01, 2010 at 11:01:04AM
> -0700, alan bryan wrote:
> > Setup:
> > 
> > server - FreeBSD 8-stable from today.  2 UFS dirs
> exported via NFS.
> > client - FreeBSD 8.0-Release.  Running a test php
> script that copies around various files to/from 2 separate
> NFS mounts.
> > 
> > Situation: 
> > 
> > script is started (forked to do 20 simultaneous runs)
> and 20 1GB files are copied to the NFS dir which works
> fine.  When it then switches to reading those files back
> and simultaneously writing to the other NFS mount I see a
> hang of 75 seconds.  If I do an "ls -l" on the NFS mount it
> hangs too.  After 75 seconds the client has reported:
> > 
> > nfs server 192.168.10.133:/usr/local/export1: not
> responding
> > nfs server 192.168.10.133:/usr/local/export1: is alive
> again
> > nfs server 192.168.10.133:/usr/local/export1: not
> responding
> > nfs server 192.168.10.133:/usr/local/export1: is alive
> again 
> > 
> > and then things start working again.  The server was
> originally FreeBSD 8.0-Release also but was upgraded to the
> latest stable to see if this issue could be avoided.
> >
> > ...
> > 
> > Any ideas on what's going on here?  What's
> causing the complete stall period of zero NFS
> activity?   Any flaws with my testing
> methods?
> 
> One thing worth asking: are there any firewall stacks
> (ipfw, ipfilter,
> or pf) in use on either the client or server?
> 
> -- 
> | Jeremy Chadwick           
>                
>        jdc at parodius.com
> |
> | Parodius Networking         
>              http://www.parodius.com/ |
> | UNIX Systems Administrator       
>           Mountain View, CA, USA |
> | Making life hard for others since 1977.   
>           PGP: 4BD6C0CB |
> 
> 


Nope, no firewalls - just 2 machines connected directly to a Dell 2716 Gbit switch.

Thanks,
Alan