From: Tom McNeal Subject: Re: Performance tuning Date: Wed, 10 Jul 2002 14:04:38 -0700 Sender: nfs-admin@lists.sourceforge.net Message-ID: <3D2CA166.CD962038@attbi.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: nfs@lists.sourceforge.net Return-path: Received: from rwcrmhc51.attbi.com ([204.127.198.38]) by usw-sf-list1.sourceforge.net with esmtp (Exim 3.31-VA-mm2 #1 (Debian)) id 17SOaM-0003Oj-00 for ; Wed, 10 Jul 2002 14:01:18 -0700 To: David Dougall Errors-To: nfs-admin@lists.sourceforge.net List-Help: List-Post: List-Subscribe: , List-Id: Discussion of NFS under Linux development, interoperability, and testing. List-Unsubscribe: , List-Archive: Hi - I gleaned that tuning info from the SPECsfs and SPECweb99 benchmarks, and documented it on the Mission Critical Linux servers that are still kept on line: http://www.missioncriticallinux.com/orph/ServerNotes.pdf The latest howtos, which have been getting updated over the last few months, and are just about ready to go, contain an updated discussion about [rw]mem_*, where I use the same examples, but note that they apply to both read and write parameters. As for limits, my paper notes much higher values than I was really willing to state in the howto. Note that benchmarks are often not real-world environments (I should probably remove the "often" qualifier), so be sure to treat these suggestions with a bit of skepticism. I also corrected the fragmentation part to refer to all kernels. The main thing to look for is MTU, plus the number of reassambly failures noted as "reasmfails" in /proc/net/snmp, especially when you start using 32K in udp (which is probably not the best idea). Regards - Tom David Dougall wrote: > > Looking through the nfs-howto chapter 5 "Optimizing NFS Performance", I > found a few ambiguous statements and was wondering if I could get some > clarification. > There is a suggestion to increase rmem_default and rmem_max in > /proc/sys/net/core to "at least 256k". What is the limit on that? If I > have a server withs gobs of memory, how high can I increase that to still > get performance improvements. Are there some statistics I can use to > measure if increases in this are helping. Also, should I also increase > wmem_default and wmem_max. It makes no mention of that in the howto. > > With respect to Overflow of fragmented packets, it mentions the 2.2 > kernel, but never mentions the 2.4. Is it the same? If so, it might be > nice to clear that up in the howto. It also states that there is no ideal > value for this. Any suggestions for specific traffic patterns? > > Thanks > --David Dougall > > ------------------------------------------------------- > This sf.net email is sponsored by:ThinkGeek > Two, two, TWO treats in one. > http://thinkgeek.com/sf > _______________________________________________ > NFS maillist - NFS@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/nfs -- ------------------------------------------------------------ Tom McNeal trmcneal@attbi.com (650)906-0761 (cell) ------------------------------------------------------------ ------------------------------------------------------- This sf.net email is sponsored by:ThinkGeek Two, two, TWO treats in one. http://thinkgeek.com/sf _______________________________________________ NFS maillist - NFS@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nfs