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From: John Baldwin <jhb@freebsd.org>
To: freebsd-net@freebsd.org
Subject: Re: Network loss
Date: Wed, 26 Feb 2014 11:32:09 -0500
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 (bigwig.baldwin.cx); Wed, 26 Feb 2014 11:33:44 -0500 (EST)
Cc: Johan Kooijman <mail@johankooijman.com>
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On Tuesday, February 25, 2014 2:19:01 am Johan Kooijman wrote:
> Hi all,
> 
> I have a weird situation here where I can't get my head around.
> 
> One FreeBSD 9.2-STABLE ZFS/NFS box, multiple Linux clients. Once in a while
> the Linux clients loose their NFS connection:
> 
> Feb 25 06:24:09 hv3 kernel: nfs: server 10.0.24.1 not responding, timed out
> 
> Not all boxes, just one out of the cluster. The weird part is that when I
> try to ping a Linux client from the FreeBSD box, I have between 10 and 30%
> packetloss - all day long, no specific timeframe. If I ping the Linux
> clients - no loss. If I ping back from the Linux clients to FBSD box - no
> loss.
> 
> The errors I get when pinging a Linux client is this one:
> ping: sendto: File too large

EFBIG is sometimes used for drivers when a packet takes too many 
scatter/gather entries.  Since you mentioned NFS, one thing you can try is to 
disable TSO on the intertface you are using for NFS to see if that "fixes" it.

-- 
John Baldwin