From owner-freebsd-fs@FreeBSD.ORG Wed Nov 2 14:18:00 2005 Return-Path: X-Original-To: freebsd-fs@freebsd.org Delivered-To: freebsd-fs@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 1E37716A41F for ; Wed, 2 Nov 2005 14:18:00 +0000 (GMT) (envelope-from bde@zeta.org.au) Received: from mailout2.pacific.net.au (mailout2.pacific.net.au [61.8.0.115]) by mx1.FreeBSD.org (Postfix) with ESMTP id 6EE2843D45 for ; Wed, 2 Nov 2005 14:17:59 +0000 (GMT) (envelope-from bde@zeta.org.au) Received: from mailproxy2.pacific.net.au (mailproxy2.pacific.net.au [61.8.0.87]) by mailout2.pacific.net.au (8.13.4/8.13.4/Debian-3) with ESMTP id jA2EHrnI016238; Thu, 3 Nov 2005 01:17:53 +1100 Received: from epsplex.bde.org (katana.zip.com.au [61.8.7.246]) by mailproxy2.pacific.net.au (8.13.4/8.13.4/Debian-3) with ESMTP id jA2EHpW4015639; Thu, 3 Nov 2005 01:17:51 +1100 Date: Thu, 3 Nov 2005 01:17:51 +1100 (EST) From: Bruce Evans X-X-Sender: bde@epsplex.bde.org To: Ivan Voras In-Reply-To: <20051101114150.X90580@geri.cc.fer.hr> Message-ID: <20051103011024.R7399@epsplex.bde.org> References: <20051030183340.B19470@geri.cc.fer.hr> <46D894BD-16E0-4CBA-B40A-EEBAAC2547D2@classicalguitar.net> <20051031191139.J38757@delplex.bde.org> <20051031160354.G67271@geri.cc.fer.hr> <20051101042444.K40281@delplex.bde.org> <20051031201719.S68800@geri.cc.fer.hr> <20051101141726.W41623@delplex.bde.org> <20051101114150.X90580@geri.cc.fer.hr> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Cc: freebsd-fs@freebsd.org Subject: Re: ext2 large_file X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 02 Nov 2005 14:18:00 -0000 On Tue, 1 Nov 2005, Ivan Voras wrote: > On Tue, 1 Nov 2005, Bruce Evans wrote: > >> On Mon, 31 Oct 2005, Ivan Voras wrote: > [for ext2fs under FreeBSD] >> first few cylinder groups full and the rest unused, where Linux would >> use all the groups fairly evenly. > > Not so good. I suppose this is not easaly fixable? Not very easily, but not very uneasily either. We can either obtain a block allocator from NetBSD (I think it is similar to ffs's, but specialized to ext2fs), or use the current Linux allocator (I think we have an old version already -- ISTR a comment saying that it is used for checking only). >> - ext2fs is about twice as slow as the other 2 (worse for non-async >> writes). >> It is mostly because the block size is very small, and although this >> only necessarily costs extra CPU to do clustering, FreeBSD is optimized >> for ffs's default block size and does pessimal things with ext2fs's >> smaller sizes. > > These effects are also very noticable with NTFS (default block size=4096 for > all/most partition sizes) and FAT32 on smaller drives (where bs=4096 fits FAT > in 8MB). 4K isn't too bad, except possibly on arches with a page size of 8K -- see my benchmark output for msdosfs. Clustering is certainly required to get good results for large files. Bruce