From: "Lever, Charles" Subject: RE: 2.4.20-rc1 NFS/TCP client (still) hangs running dbench 2.0 Date: Sat, 2 Nov 2002 06:57:47 -0800 Sender: nfs-admin@lists.sourceforge.net Message-ID: <6440EA1A6AA1D5118C6900902745938E07D5503C@black.eng.netapp.com> Mime-Version: 1.0 Content-Type: text/plain Cc: nfs@lists.sourceforge.net, Andrew Ryan Return-path: Received: from mx01.netapp.com ([198.95.226.53]) by usw-sf-list1.sourceforge.net with esmtp (Exim 3.31-VA-mm2 #1 (Debian)) id 187zix-0007yV-00 for ; Sat, 02 Nov 2002 06:58:07 -0800 To: "'trond.myklebust@fys.uio.no'" 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: > >>>>> " " == Andrew Ryan writes: > > > However, according to nfsstat -c's "Client rpc stats", I'm > > getting around a 10:1 ratio of retransmits to calls. That's > > bad. I get 0 retransmits when using 2.4.19+kmap1, and any > > previous kernel I've ever tried TCP mounting with. I checked > > 2.4.20rc1-vanilla and it does the same thing, so it's not the > > latest patch. > > It is probably just the (known) accounting error in the > 'retransmit' statistics. Try applying the patch > http://www.fys.uio.no/~trondmy/src/2.4.20-pre9/linux-2.4.20-01-call_start.dif > if it bothers you. call_start changes the way RPCs are counted, not how retransmits are counted. i suspect andrew is seeing partial transmits -- in 2.4.20-pre, partial TCP transmissions are counted as retransmits. in fact, it looks like the patch i sent in august for 2.4.20-pre5 to fix xprt_write_space was never applied to 2.4. trond, can you ping marcelo on this? it's a pretty important performance enhancement that should be in 2.4.20. > Note: the TCP timeout + retransmits will (unlike UDP) be of the order > of 60 seconds, so if these were real retransmits, you'd be seeing a > *very* noticeable slowdown... except that mount is broken and sets a 6 second TCP retransmission default rather than the standard value of 60 seconds. ------------------------------------------------------- This sf.net email is sponsored by: See the NEW Palm Tungsten T handheld. Power & Color in a compact size! http://ads.sourceforge.net/cgi-bin/redirect.pl?palm0001en _______________________________________________ NFS maillist - NFS@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nfs