From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from plane.gmane.org ([80.91.229.3]:38250 "EHLO plane.gmane.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754600AbcFHGOH (ORCPT ); Wed, 8 Jun 2016 02:14:07 -0400 Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1bAWkd-00014C-03 for linux-btrfs@vger.kernel.org; Wed, 08 Jun 2016 08:14:03 +0200 Received: from ip-64-134-228-1.public.wayport.net ([64.134.228.1]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Wed, 08 Jun 2016 08:14:02 +0200 Received: from 1i5t5.duncan by ip-64-134-228-1.public.wayport.net with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Wed, 08 Jun 2016 08:14:02 +0200 To: linux-btrfs@vger.kernel.org From: Duncan <1i5t5.duncan@cox.net> Subject: Re: btrfs Date: Wed, 8 Jun 2016 06:13:46 +0000 (UTC) Message-ID: References: <1464819934.6742.71.camel@scientia.net> <1464975482.6679.11.camel@scientia.net> <6f18c0d1-8ac5-c325-0ba8-ffb949c54554@gmail.com> <1465005092.6648.39.camel@scientia.net> <1465160205.6702.38.camel@scientia.net> <20160605210721.GH24492@carfax.org.uk> <1465162317.6702.53.camel@scientia.net> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-btrfs-owner@vger.kernel.org List-ID: Christoph Anton Mitterer posted on Sun, 05 Jun 2016 23:31:57 +0200 as excerpted: >> > Wasn't it said, that autodefrag performs bad for anything larger than >> > ~1G? >> >>    I don't recall ever seeing someone saying that. Of course, I may >> have forgotten seeing it... > I think it was mentioned below this thread: > http://thread.gmane.org/gmane.comp.file-systems.btrfs/50444/focus=50586 > and also implied here: > http://article.gmane.org/gmane.comp.file-systems.btrfs/51399/match=autodefrag+large+files Yes. I was rather surprised to see Hugo say he doesn't recall seeing anyone state that autodefrag performs poorly on large (from half gig) files, and that its primary recommended use is for smaller database files such as the typical quarter-gig or smaller sqlite files created by firefox and various mail clients (thunderbird, evolution). Because I've both seen and repeated that many times, myself, and indeed, the wiki's mount options page used to say effectively that. And actually, looking at the history of the page, it was Hugo that deleted the wording to the effect that autodefrag didn't work well on large database or VM files.. https://btrfs.wiki.kernel.org/index.php?title=Mount_options&diff=29268&oldid=28191 So if he doesn't remember it... But perhaps Hugo read it as manual defrag, not autodefrag, as I don't remember manual defrag ever being associated with that problem (tho it did and does still have the reflinks/snapshots problem, but that's a totally different issue). Meanwhile, it's news to me that autodefrag doesn't have that problem any longer... -- Duncan - List replies preferred. No HTML msgs. "Every nonfree program has a lord, a master -- and if you use the program, he is your master." Richard Stallman