Re: NFS performance

On Sat, 15 Aug 2009, Kirk Goins wrote:

Just to chime in late here... I've a number of systems over the years
with speed and duplex set to *auto and had terrible performance. The
400/iSeries/whatever reported in that it was running 100/FULL but wasn't
getting anywhere near that. Until the recently I've always hard coded
both the SW and NIC where possible. Here's a pretty simple test that

I changed the settings from *AUTO/*AUTO to 100M/*FULL.

will verify. Use Windows to get to the IFS folder where iSeries Access
lives. ( /QIBM/ProdData/CA400/Express/Install/Image ). Now select all
the files in that folder, right-click drag and drop to a folder on your
pc and specify COPY... If it's a true 100MB connection, the copy will
take 3 minutes or less ( on V5Rx ). If it bad, Windows will typically
give you an estimated time to complete of 100+ minutes at which I bail
on the copy. Another test I stumbled into was poor FTP performance. I

I don't have windows, so I did an ftp of all the files in /QIBM/ProdData/CA400/Express/Install/Image to try to duplicate the above test. All files transferred in about 1 minute. Total amount of data transferred: 241M. I also tested ftp with a 700MB file and it also completed in around one minute twenty seconds.

Considering the above, I don't think that link/line speed is the problem.

I then thought it would be useful to test NFS performance between the linux box in question and another linux machine. I copied the same 700MB file between machines using NFS and this took 33 seconds.

was trying to FTP some Image Catalogs between a 800 and an E4A it was
taking forever, like an hour per CD image. Found a cheap SOHO class
switch in the loop between the systems and got the 800 off it and my FTP
times fell to around 75 seconds per image.

No rogue switches/hubs here. All machines in question are on the same gigabit switch (D-Link DGS-1016D).

James Rich

if you want to understand why that is, there are many good books on
the design of operating systems. please pass them along to redmond
when you're done reading them :)
- Paul Davis on ardour-dev