From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda1.sgi.com [192.48.157.11]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id oAMN5uwK122884 for ; Mon, 22 Nov 2010 17:05:56 -0600 Received: from mail.internode.on.net (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id DD03613E1A4B for ; Mon, 22 Nov 2010 15:07:31 -0800 (PST) Received: from mail.internode.on.net (bld-mail15.adl6.internode.on.net [150.101.137.100]) by cuda.sgi.com with ESMTP id hGBapbuCKtVpZqs5 for ; Mon, 22 Nov 2010 15:07:31 -0800 (PST) Date: Tue, 23 Nov 2010 10:07:28 +1100 From: Dave Chinner Subject: Re: Is xfs defrag *reliably* aligned to stripes? Message-ID: <20101122230728.GI13830@dastard> References: <4CEAC203.9040800@shiftmail.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <4CEAC203.9040800@shiftmail.org> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: Spelic Cc: xfs@oss.sgi.com On Mon, Nov 22, 2010 at 08:18:27PM +0100, Spelic wrote: > Hello xfs people, > > does the xfs defrag (xfs_fsr, I think) reliably aligns files to stripes? No, the allocator does best effort attempts only. > Does it do that? Will it do that in the future? If the filesystem has large enough contiguous free space extents, it will align the initial allocation to stripe unit, but once you age the filesystem there is no guarantee this will be possible. use "xfs_bmap -vvp" to look at the alignment of files. Of course, this all only works if you mkfs your filesystem with sunit/swidth or su/sw parameters.... Cheers, Dave. -- Dave Chinner david@fromorbit.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs