Re: [gentoo-user] Re: NFS vs. jumbo frames
Hi Francesco, on Monday, 2007-04-23 at 21:58:18, you wrote: Based on my experience I would add to verify also the upper MTU value really supported. According to Documentation/networking/e1000.txt, the adapters should all support 16K frames. The limiting factor would be the switch's 9K limit, but I've stayed below that as well. cheers! Matthias -- I prefer encrypted and signed messages. KeyID: FAC37665 Fingerprint: 8C16 3F0A A6FC DF0D 19B0 8DEF 48D9 1700 FAC3 7665 pgptGqJm9zDOA.pgp Description: PGP signature
[gentoo-user] Re: NFS vs. jumbo frames
kashani kashani-list at badapple.net writes: Just curious: What kind of network (layer 2) is this that allows an MTU of 9000? Uwe It sounds like Gigabit Ethernet to me. Keep in mind that not all fastE or gigE switches support jumbo frames. Additionally not all cards support jumbo frames either though you can certainly set them to an MTU of 9000 and watch things break. To the original poster, I'd do some googling and verify that all the network cards and switches involved can do jumbo frames and that it is enabled on each device as needed. kashani Does NFS have any negotiations to determine if jumbo frames can work between 2 system, then use a smaller mtu if a larger (jumbo) mtu is not suppported between devices? James -- [EMAIL PROTECTED] mailing list
Re: [gentoo-user] Re: NFS vs. jumbo frames
On 23 April 2007, ames wrote: kashani kashani-list at badapple.net writes: Just curious: What kind of network (layer 2) is this that allows an MTU of 9000? Uwe It sounds like Gigabit Ethernet to me. Keep in mind that not all fastE or gigE switches support jumbo frames. Additionally not all cards support jumbo frames either though you can certainly set them to an MTU of 9000 and watch things break. To the original poster, I'd do some googling and verify that all the network cards and switches involved can do jumbo frames and that it is enabled on each device as needed. kashani Does NFS have any negotiations to determine if jumbo frames can work between 2 system, then use a smaller mtu if a larger (jumbo) mtu is not suppported between devices? Don't stare at NFS. It's too high a layer in the TCP/IP stack. And yes, it can deal with large packets. You can use NFS with localhost (127.0.0.1), right? That one usually has an MTU of 16,436. The real issues with MTUs occur at layer 2 (ethernet or whatever you are using), IP (fragmentation and de-fragmentation) and ICMP (MTU discovery). Uwe -- The Informal Linux Group Namibia: http://www.linux.org.na SysEx (Pty) Ltd.: http://www.SysEx.com.na -- [EMAIL PROTECTED] mailing list
[gentoo-user] Re: NFS vs. jumbo frames
On Monday 23 April 2007, kashani wrote: Tony Stohne wrote: -BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Uwe Thiem said the following on 2007-04-23 17:53: Just curious: What kind of network (layer 2) is this that allows an MTU of 9000? Uwe It sounds like Gigabit Ethernet to me. Keep in mind that not all fastE or gigE switches support jumbo frames. Additionally not all cards support jumbo frames either though you can certainly set them to an MTU of 9000 and watch things break. Some cards do support jumbo frames, but up to values lower than 9000, for example I set up a NFS over a gbit link with jumbo frames with an MTU of 7200 because this was the lower common. To the original poster, I'd do some googling and verify that all the network cards and switches involved can do jumbo frames and that it is enabled on each device as needed. kashani Based on my experience I would add to verify also the upper MTU value really supported. Ciao Francesco -- Linux Version 2.6.20-gentoo-r6, Compiled #2 PREEMPT Fri Apr 20 17:31:11 CEST 2007 One 2.2GHz AMD Athlon 64 Processor, 2GB RAM, 4408.86 Bogomips Total aemaeth -- [EMAIL PROTECTED] mailing list
Re: [gentoo-user] Re: NFS vs. jumbo frames
You can also fiddle with the rsize, wsize NFS mount parameters. -- Fabio A. Correa D. Physics Dept, Universidad Nacional, Bogota, Colombia [EMAIL PROTECTED] [EMAIL PROTECTED] [EMAIL PROTECTED] My webpage and OpenPGP key at http://facorread.150m.com My alexandria.cc address is not available anymore. -- [EMAIL PROTECTED] mailing list
