From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: with ECARTIS (v1.0.0; list xfs); Wed, 23 Jan 2008 16:28:29 -0800 (PST) Received: from larry.melbourne.sgi.com (larry.melbourne.sgi.com [134.14.52.130]) by oss.sgi.com (8.12.11.20060308/8.12.11/SuSE Linux 0.7) with SMTP id m0O0SL7l016072 for ; Wed, 23 Jan 2008 16:28:23 -0800 Date: Thu, 24 Jan 2008 11:28:28 +1100 From: David Chinner Subject: Re: xfs_rapair memory requirement per TB Message-ID: <20080124002828.GC155259@sgi.com> References: <1201042882.32649.256.camel@holwrs01.bp.com> <20080123085339.GB12435@p15145560.pureserver.info> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080123085339.GB12435@p15145560.pureserver.info> Sender: xfs-bounce@oss.sgi.com Errors-to: xfs-bounce@oss.sgi.com List-Id: xfs To: Ralf Gross Cc: Barry Naujok , xfs@oss.sgi.com On Wed, Jan 23, 2008 at 09:53:39AM +0100, Ralf Gross wrote: > Barry Naujok schrieb: > > > > > >Reading the "Repairing a possibly incomplete xfs_growfs command?" thread > > >this month makes me wonder if there is some type of rough formula or > > >guesstimation cheat sheet to figure out how much memory and swap one > > >would need for an xfs_repair given a file system with many terabytes. > > > > > > > > >Say I have an 8TB LUN that needs an xfs_repair. What would be the rough > > >memory requirements and swap space? > > > > > > > General rule of thumb at the moment is 128MB of RAM/TB of filesystem > > plus 4MB/million inodes on that filesystem. > > Did this change lately? I found the rule of thumb: 2 GB RAM for 1 TB > of disk storage + some RAM per x inodes. The above is based on actual theoretical usage, the below: > http://oss.sgi.com/archives/xfs/2005-08/msg00045.html was based on reported usage on during live repair runs. I think Barry discovered the difference to be things external to repair such as heap fragmentation and has since corrected the worst of the issues so requirements are, in general, much closer to the theoretical numbers now. Cheers, Dave. -- Dave Chinner Principal Engineer SGI Australian Software Group