SUMMARY: Slow file reads on E4500

From: David E. Schwarze (dxschwarze@link-us.net)
Date: Thu Aug 17 2000 - 11:30:09 CDT


First off, I want to thank everyone for the helpful replies:

Chandra Kalle
Frank Smith
Bill Hathaway
Patrick Shannon
Brent Killioni
Joe Muldoon
Ric Anderson
Michael Miller
Daniel Lorenzini
Hoang Nguyen

Hope I didn't miss anyone. The problem was that file reads from the E4500
were excrutiatingly slow, in the neighborhood of 5-30KB/sec. Writes to the
same machine were very fast.

As most of you suspected, the problem was with half vs. full duplex. I had
checked the setting of the card with "ndd /dev/qfe link_mode" and it
reported 1 for full duplex so I didn't think that was the problem. The
solution was provided by Ric Anderson, who told me to do the following
before checking the card:

ndd -set /dev/qfe instance 0

After executing this, another check of link_mode returned 0. I guess I had
been looking at the wrong port on the qfe card? I'm still not sure what
instance refers to. In any case, I reset the interface with the following
set of commands provided by Chandra Kalle:

ndd -set /dev/qfe adv_10fdx_cap 0
ndd -set /dev/qfe adv_10hdx_cap 0
ndd -set /dev/qfe adv_100fdx_cap 1
ndd -set /dev/qfe adv_100hdx_cap 0
ndd -set /dev/qfe adv_autoneg_cap 0

and added a corresponding set of commands to /etc/system, provided by
Michael Miller, so that the 4500 will come up the same way next time it is
booted:

set qfe:qfe_adv_autoneg_cap=0
set qfe:qfe_adv_100T4_cap=0
set qfe:qfe_adv_100fdx_cap=1
set qfe:qfe_adv_100hdx_cap=0
set qfe:qfe_adv_10fdx_cap=0
set qfe:qfe_adv_10hdx_cap=0

Hardwiring the card to 100mbit full duplex in this manner fixed the problem
- read access is now blazing fast.

Finally, Bill Hathaway suggested applying patch 105379-6 which deals with
slow nfs reads. I checked my installed patches with patchadd -p | grep
105379 and this patch is not present. Next time I do a level 0 backup on
this sytem I will apply the patch, set the card back to auto and see if the
problem is still there.

Here is my original message:
> We are having a problem with our E4500 system. It is running Solaris 2.6,
> has 6 cpus, 6GB RAM, and is attached to an A5200 disk array via gigabit
> ethernet. We are using Veritas Volume Manager, but I don't know the
> details of how the volumes are set up at this time. The system and LAN
> are lightly loaded.
>
> The problem is this: any time a file is read over the network from this
> machine, the transfer rate is extremely slow. Anywhere from 5 to 30 KBps.
> Writes are at normal speeds of 1000-6000KBps. This was tested using FTP.

-David

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