Date: Wed, 24 Jul 2002 10:15:09 -0700 (PDT) From: Matthew Dillon <dillon@apollo.backplane.com> To: "Jaime Bozza" <jbozza@thinkburst.com> Cc: <stable@FreeBSD.ORG>, "'Olaf R'" <olaf@keghouse.net> Subject: Re: RE: Abominable NFSv3 read performance / FreeBSD server / Solaris client Message-ID: <200207241715.g6OHF9Ne028675@apollo.backplane.com> References: <022101c2332c$729a5610$6401010a@bozza>
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:..
:FreeBSD 4.6-STABLE server, default nfsd settings, tcp.sendspace=32768
:Solaris 8 client (SparcStation 20), default settings, default options
:for the mount.
:bigfile is 64953143 bytes
:
:(Solaris 8 with NFSv3 defaults to a 32768 read buffer size, rsize=32768)
:
:(on Solaris system)
:mount server:/export /mnt/server
:time dd if=/mnt/server/bigfile of=/dev/null bs=64k
:
:returns:
:991+1 records in
:991+1 records out
:0.05u 1.68s 2:29.76 1.1%
:
:
:mount -o rsize=16384 server:/export /mnt/server
:time dd if=/mnt/server/bigfile of=/dev/null bs=64k
:
:returns:
:991+1 records in
:991+1 records out
:0.03u 3.11s 0:19.61 16.0%
:
:
:rsize=8192 (0.00u 2.50s 0:33.37 7.4%)
:rsize=12288 (0.07u 3.00s 0:28.95 10.6%)
Well, Solaris is issuing four NFS read rpc's. With the original trace
and a buffer size of 8K this will cause FreeBSD to push out a little over
32K worth of TCP. This implies that a 32K TCP send and receive window is
not sufficient.
:
:Increasing tcp.sendspace on the server did not seem to change the times
:all that much. (the default 32768 read buffer would have the same 780
:bytes in the Send-Q you talked about below)
Increase sendspace on the server and recvspace on the client, and make
sure they've actually increased. A tcpdump should show much larger window
advertisements from the solaris client, and netstat -tn on the FreeBSD box
during the transfer (over and over again) should show that the FreeBSD box
is able to queue up more then 32K.
-Matt
:
:If you want me to run additional tests or outputs, I'd be happy to.
:
:Jaime Bozza
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