From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lists.gentoo.org (pigeon.gentoo.org [208.92.234.80]) by finch.gentoo.org (Postfix) with ESMTP id 775CF1381F4 for ; Tue, 14 Aug 2012 21:06:26 +0000 (UTC) Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id A6AD121C0C8; Tue, 14 Aug 2012 21:04:15 +0000 (UTC) Received: from mail-vb0-f53.google.com (mail-vb0-f53.google.com [209.85.212.53]) by pigeon.gentoo.org (Postfix) with ESMTP id 3A26A21C0B2 for ; Tue, 14 Aug 2012 20:57:13 +0000 (UTC) Received: by vbbfc26 with SMTP id fc26so895059vbb.40 for ; Tue, 14 Aug 2012 13:57:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; bh=rFlhJdNRGNEClL60O5gfYsd7N6ZuOR93SKrcyIgisXU=; b=CenWBzXbzhs69M8f3jm/cHTlpO9UPkMmPA4HmcZvQxZyAWcH85LZJKSC9oxgc8CcMY +pOCdT3D0tIWfZeFKeQK25mQOCRwcxtSLjU97jMLapKXJaj40L+FkL2hNbvNO7AOEHw8 GArdLcz4xLvt263wzTdGWEhS5b2b2HHvgaj1szGNyHpUJuwR+Xzkc+wN8ZyjcGXQ1g/T tPT5UBBB9N/nKuX9/a5n5VEB7geOr8Vm0o/iHg7GFd/yLzLepqD026yQA010rzPozvNF TSnM6ULVrMPohcvL/TOc/2vqfwkk32Cm2SwEfBOeVLRLYVl7P5HWqEbiokrEMaheAI5v G9gQ== Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-user@lists.gentoo.org Reply-to: gentoo-user@lists.gentoo.org MIME-Version: 1.0 Received: by 10.58.189.73 with SMTP id gg9mr1280853vec.26.1344977832601; Tue, 14 Aug 2012 13:57:12 -0700 (PDT) Received: by 10.59.1.4 with HTTP; Tue, 14 Aug 2012 13:57:12 -0700 (PDT) In-Reply-To: References: <2915543.UzKMyIEiK0@energy> <502A8FD9.5030505@hadt.biz> Date: Tue, 14 Aug 2012 15:57:12 -0500 Message-ID: Subject: Re: [gentoo-user] Fast file system for cache directory with lot's of files From: Alecks Gates To: gentoo-user@lists.gentoo.org Content-Type: text/plain; charset=ISO-8859-1 X-Archives-Salt: 9c27e38a-8433-4acb-a452-6b90aba9a745 X-Archives-Hash: 30985504c8106a687e7c928ba9685d3e On Tue, Aug 14, 2012 at 3:17 PM, Michael Mol wrote: > On Tue, Aug 14, 2012 at 3:55 PM, Alecks Gates wrote: >> >> On Tue, Aug 14, 2012 at 12:50 PM, Michael Hampicke >> wrote: >> > Am 14.08.2012 19:42, schrieb Volker Armin Hemmann: >> >> Am Dienstag, 14. August 2012, 13:21:35 schrieb Jason Weisberger: >> >>> Sure, but wouldn't compression make write operations slower? And >> >>> isn't he >> >>> looking for performance? >> >> >> >> not really. As long as the CPU can compress faster than the disk can >> >> write >> >> stuff. >> >> >> >> More interessting: is btrfs trying to be smart - only compressing >> >> compressible >> >> stuff? >> >> >> > >> > It does do that, but letting btrfs check if the files are already >> > compressed, if you know, that they are compressed, is a waste of cpu >> > cycles :) >> > >> >> Also look into the difference between compress and compress-force[0]. >> I wonder how much overhead checking whether or not to compress a file >> costs. I use mount options similar to Helmut and get great results: >> defaults,autodefrag,space_cache,compress=lzo,subvol=@,relatime >> >> But most of my data is compressible. Compression makes such a huge >> difference, it surprises me. Apparently on this Ubuntu system it >> automatically makes use of all files on / as a subvolume in "@". >> Interesting. > > > Huge difference, how? > > Could we see some bonnie++ comparisons between the various configurations > we've discussed for ext4 and btrfs? Depending on the results, it might be > getting time for me to take the plunge myself. > > -- > :wq Check out some of the benchmarks on Phoronix[0]. It's definitely not a win-win scenario, but it seems to be great at random writes and compiling. And a lot of those wins are without compress=lzo enabled, so it only gets better. I'm not going to say it's the absolute best out there (because it isn't, of course), but it's at least worth checking into. I'm using a standard 2.5" HDD like in this[1] so perhaps that's why I see the results. [0] http://www.phoronix.com/scan.php?page=search&q=Btrfs [1] http://www.phoronix.com/scan.php?page=article&item=btrfs_old_linux31