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Date:      Fri, 13 Sep 2013 23:08:11 -0400
From:      Barney Cordoba <barney_cordoba@yahoo.com>
To:        Mike Tancsa <mike@sentex.net>
Cc:        FreeBSD Net <net@freebsd.org>, Rick Macklem <rmacklem@uoguelph.ca>, David Wolfskill <david@catwhisker.org>
Subject:   Re: TSO help or hindrance ?  (was Re: TSO and FreeBSD vs Linux)
Message-ID:  <596C2208-BC2A-417B-B46F-300D5886C087@yahoo.com>
In-Reply-To: <522FA2C3.7010109@sentex.net>
References:  <979862494.17918795.1378299005617.JavaMail.root@uoguelph.ca> <52275136.1010105@sentex.net> <1378852936.95477.YahooMailNeo@web121601.mail.ne1.yahoo.com> <522FA2C3.7010109@sentex.net>

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Didn't read down far enough.  There are def issues and gains are probably mo=
stly in a lab with  9k frames. Turn it off. CPUs and buses are fast.=20

BC


On Sep 10, 2013, at 6:52 PM, Mike Tancsa <mike@sentex.net> wrote:

> On 9/10/2013 6:42 PM, Barney Cordoba wrote:
>> NFS has been broken since Day 1, so lets not come to conclusions about
>> anything
>> as it relates to NFS.
>=20
> iSCSI is NFS ?
>=20
>    ---Mike
>=20
>>=20
>> BC
>>=20
>> ------------------------------------------------------------------------
>> *From:* Mike Tancsa <mike@sentex.net>
>> *To:* Rick Macklem <rmacklem@uoguelph.ca>
>> *Cc:* FreeBSD Net <net@freebsd.org>; David Wolfskill <david@catwhisker.or=
g>
>> *Sent:* Wednesday, September 4, 2013 11:26 AM
>> *Subject:* TSO help or hindrance ? (was Re: TSO and FreeBSD vs Linux)
>>=20
>> On 9/4/2013 8:50 AM, Rick Macklem wrote:
>>> David Wolfskill wrote:
>>>>=20
>>>>=20
>>>> I noticed that when I tried to write files to NFS, I could write
>>>> small
>>>> files OK, but larger ones seemed to ... hang.
>>>> * "ifconfig -v em0" showed flags TSO4 & VLAN_HWTSO turned on.
>>>> * "sysctl net.inet.tcp.tso" showed "1" -- enabled.
>>>>=20
>>>> As soon as I issued "sudo net.inet.tcp.tso=3D0" ... the copy worked
>>>> without
>>>> a hitch or a whine.  And I was able to copy all 117709618 bytes, not
>>>> just
>>>> 2097152 (2^21).
>>>>=20
>>>> Is the above expected?  It came rather as a surprise to me.
>>>>=20
>>> Not surprising to me, I'm afraid. When there are serious NFS problems
>>> like this, it is often caused by a network fabric issue and broken
>>> TSO is at the top of the list w.r.t. cause.
>>=20
>>=20
>> I was just experimenting a bit with iSCSI via FreeNAS and was a little
>> disappointed at the speeds I was getting. So, I tried disabling tso on
>> both boxes and it did seem to speed things up a bit.  Data and testing
>> methods attached in a txt file.
>>=20
>> I did 3 cases.
>>=20
>> Just boot up FreeNAS and the initiator without tweaks.  That had the
>> worst performance.
>> disable tso on the nic as well as via sysctl on both boxes. That had the
>> best performance.
>> re-enable tso on both boxes. That had better performance than the first
>> case, but still not as good as totally disabling it.  I am guessing
>> something is not quite being re-enabled properly ? But its different
>> than the other two cases ?!?
>>=20
>> tgt is FreeNAS-9.1.1-RELEASE-x64 (a752d35) and initiator is r254328 9.2
>> AMD64
>>=20
>> The FreeNAS box has 16G of RAM, so the file is being served out of cache
>> as gstat shows no activity when sending out the file
>>=20
>>=20
>>=20
>>    ---Mike
>>=20
>>=20
>> --=20
>> -------------------
>> Mike Tancsa, tel +1 519 651 3400
>> Sentex Communications, mike@sentex.net <mailto:mike@sentex.net>
>> Providing Internet services since 1994 www.sentex.net
>> Cambridge, Ontario Canada  http://www.tancsa.com/
>>=20
>> _______________________________________________
>> freebsd-net@freebsd.org <mailto:freebsd-net@freebsd.org> mailing list
>> http://lists.freebsd.org/mailman/listinfo/freebsd-net
>> To unsubscribe, send any mail to "freebsd-net-unsubscribe@freebsd.org
>> <mailto:freebsd-net-unsubscribe@freebsd.org>"
>>=20
>=20
>=20
> --=20
> -------------------
> Mike Tancsa, tel +1 519 651 3400
> Sentex Communications, mike@sentex.net
> Providing Internet services since 1994 www.sentex.net
> Cambridge, Ontario Canada   http://www.tancsa.com/
> _______________________________________________
> freebsd-net@freebsd.org mailing list
> http://lists.freebsd.org/mailman/listinfo/freebsd-net
> To unsubscribe, send any mail to "freebsd-net-unsubscribe@freebsd.org"



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