From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932343AbWAQSin (ORCPT ); Tue, 17 Jan 2006 13:38:43 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932348AbWAQSin (ORCPT ); Tue, 17 Jan 2006 13:38:43 -0500 Received: from lucidpixels.com ([66.45.37.187]:33180 "EHLO lucidpixels.com") by vger.kernel.org with ESMTP id S932343AbWAQSim (ORCPT ); Tue, 17 Jan 2006 13:38:42 -0500 Date: Tue, 17 Jan 2006 13:38:41 -0500 (EST) From: Justin Piszcz X-X-Sender: jpiszcz@p34 To: Trond Myklebust cc: Alan Cox , Tomasz =?iso-8859-2?Q?K=B3oczko?= , Phil Oester , linux-kernel@vger.kernel.org, apiszcz@lucidpixels.com Subject: Re: Kernel 2.6.15.1 + NFS is 4 times slower than FTP!? In-Reply-To: <1137523035.7855.91.camel@lade.trondhjem.org> Message-ID: References: <20060117012319.GA22161@linuxace.com> <1137521483.14135.59.camel@localhost.localdomain> <1137523035.7855.91.camel@lade.trondhjem.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Writing from SRC(A) -> DST(B). I have not tested reading, but as I recall there were similar speed issues going the other way too, although I have not tested it recently. Justin. On Tue, 17 Jan 2006, Trond Myklebust wrote: > On Tue, 2006-01-17 at 13:24 -0500, Justin Piszcz wrote: >> Alan, is it normal for FTP to be 2x as fast as NFS? >> With 100mbps, I never seemed to have any issues, but with GIGABIT I >> definitely see all sorts of weird issues. > > Reading or writing? > > The readahead algorithm has been borken in 2.6.x for at least the past 6 > months. It leads to NFS collapsing down to 4k reads on the wire instead > of doing 32k or 64k. > An effort was made to look at fixing this, but it turns out that nobody > really understands the current messy implementation, and so progress has > been slow. > > Cheers, > Trond >