[OpenAFS] Heavy performance loss on gigabit ethernet

Theodore F Vaida ted@contrailservices.com
Wed, 18 Aug 2004 11:45:59 -0600


> I haven't seen Jumbo Frames mentioned, yet. Are you certain that isn't 
> turned on in the server or the switch it's connected to where it 
> shouldn't be?

The Gigabit switch allows jumbo frames and as far as I can tell cannot 
be turned off - the only control settings on the Layer 2 switch are for 
duplex and flow control (802.3 back pressure).  The 100Mb switch also 
supports jumbo frames and is an unmanaged device. The only control over 
jumbo frames would be the NIC drivers from what I know.

Derrick suggested using the -nojumbo option on the fileservers and I'm 
check on Head Of Line blocking to see if that might also help since the 
logs show some complaints from the clients about 'out of order' 
packets.

I'm also wondering if the iproute2 tools and a traffic shaper on the 
fileserver which rate-limits the traffic to the 100Mb clients might be 
worth trying?