From: JTNishimoto (jerry@primal.ucdavis.edu)
Date: Thu Jul 10 2003 - 17:40:32 EDT
Tru64 Managers,
Thanks to Grant Schoep, Ron Bramblett, Pat Barrowclough!
The responses favored using 100 Full Duplex.
With the nics configured for both systems at 100 full duplex and the
switch to autonegotiate. We saw the following types of errors:
NFS3 server system.name not responding still trying
After setting the switch to 100 full duplex the errors went away and
systems ran without any noticable problems. I then decided to test the
systems and the switch preset at 100 half duplex. Again, the systems ran
without any noticable problems or performance differences.
Anyone care to comment on why half and full should perform about the
same?
Iperf (http://dast.nlanr.net/Projects/Iperf) was used to test the network
performance.
Modifying the subsystem inet parameter tcp_sendspace and tcp_recvspace to
65536 helped improve the performance.
The most helpful hint I can pass along is:
*** Turn off autonegotiation of NICS and Hubs/Switches.
Jerry
Jerry T. Nishimoto Mailing address:
Facility Manager
Location: Rm 3128 SS&H Agricultural & Resource Economics
e-mail: jerry@primal.ucdavis.edu University of California Davis
Phone: (530)752-1598 One Shields Ave
Fax: (530)752-5614 Davis, California 95616-8512
-----Original Message-----
From: JTNishimoto [mailto:jerry@primal.ucdavis.edu]
Sent: Tuesday, July 01, 2003 8:43 AM
To: tru64-unix-managers@ornl.gov
Subject: Half vs Full Duplex for NFS
Hi Tru64's,
Our network was recently upgraded to 100bt Foundry switches. My question
is how should we configure the NIC's for our DS10's. They were configured
at 10 half duplex. Is it save or reliable to configure the NICS at 100
full for NFS?
>From GSchoep@storm.L-3Com.com Thu Jul 10 13:31:59 2003
Date: Tue, 1 Jul 2003 15:59:17 -0400
From: "Schoep, Grant @ STORM" <GSchoep@storm.L-3Com.com>
To: 'JTNishimoto' <jerry@primal.ucdavis.edu>, tru64-unix-managers@ornl.gov
Subject: RE: Half vs Full Duplex for NFS
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I don't see why not. I've heard some people say they have issues with some
switches, but all my Alpha machines here I have always just set them to auto
negotiate the connect and they always get 100 Full Dup. Never ever seen an
issue with any computer set to auto(PC,SGI, Sun you name it). Though there
are tons of people out there who swear that auto-negotiate is a mess. Though
I've always just been using 3Com switches.
In any event, there should be no reason to be sitting at 10 half duplex. Set
it to auto or configure each one to 100 FD, assuming the switch you have
does 100 FD.
-grant
>From bramblet@fuller.com Thu Jul 10 13:34:33 2003
Date: Tue, 01 Jul 2003 10:22:50 -0500
From: Ron Bramblett <bramblet@fuller.com>
To: JTNishimoto <jerry@primal.ucdavis.edu>
Subject: Re: Half vs Full Duplex for NFS
Jerry,
We have cisco switches and they will auto negotiate and we normally let our equipment auto
negotiate. I am not sure about the servers.
--
Ron Bramblett
Sys Admin
Fuller Brush Company
>From LHERCAUD@bouyguestelecom.fr Thu Jul 10 13:34:44 2003
Date: Tue, 1 Jul 2003 18:04:47 +0200
From: LHERCAUD@bouyguestelecom.fr
To: jerry@primal.ucdavis.edu
Subject: RE: Half vs Full Duplex for NFS
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Go for 100 FULL ! why not ?
>From Pat.Barrowclough@solves-it.co.uk Thu Jul 10 13:34:52 2003
Date: Tue, 1 Jul 2003 18:35:12 +0100
From: Pat Barrowclough <Pat.Barrowclough@solves-it.co.uk>
To: JTNishimoto <jerry@primal.ucdavis.edu>
Subject: RE: Half vs Full Duplex for NFS
Jerry,
It is your network hub/switch which governs whether you can use full or half
duplex. Hubs only support half duplex because other devices share the same
segment within the hub, whereas switches separate each device onto
individual segments and can therefore support full duplex.
regards Pat
>From waldorfm@rferl.org Thu Jul 10 13:35:10 2003
Date: Wed, 02 Jul 2003 13:11:11 +0200
From: Markus Waldorf <waldorfm@rferl.org>
To: JTNishimoto <jerry@primal.ucdavis.edu>
Subject: Re: Half vs Full Duplex for NFS
Hi,
the most important thing is to make sure that the switch port and your NIC
is configured the same way, otherwise you'll loose data, see a lot of errors
including a hugh performance loss.
If the DS10 uses a 10 baseT NIC, than it was most likely designed for hubs,
which don't support full-duplex. If it is a 100 baseT, then I would suggest
to configure it for 100 full-duplex, provided the switch is configured the
same way. Full-Duplex has the advantage that there won't be any collisions
and re-transmitts, hence it does not have an error protocol. Setting NIC and
switch to auto negotiate may also work - I haven't had any problems with it
using recent NIC's and Cisco switches. Whatever you do, I would suggest to
verify that the ports work properly by asking the network admin to look for
errors, and on the system side using netstat -s.
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