I have heard this from NetApp technicians and on this list, but The only thing I found on the NetApp web page search was a reference to a switch that would overflow the buffer when translating from gigabit ethernet to fast ethernet. Someone please, point me to the bug description. We have seen the improvement, but we run GigE from client to server. None of the switches show errors or severe packet loss. The server shows packet loss, but how is that decreased by smaller read and write sizes on clients? Our switch software is supposed to be up to date. We see the problem alot and run UDP strictly, so, I need a bug number or a better description of this thing, please.
I'm not complaining, I know you are correct; it does improve performance. It's measurable and significant. When I buy new equipment, I want to pinpoint this and avoid it. When fast ethernet is faster that GigE, something is bad.
From: "Magnus Swenson" magnuss@cadence.com Edward,
Try to disable TCP over NFS and only enable UDP. Also in a switched environment 10/100/1000 BT keep the xfersizes to 8192 this has proven to improve performance (at least for us). This is a known bug on certain switches, it's also listed on now.netapp.com.
Re, Magnus Swenson
Subject: Re: Slow writes