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 q8KMbiF0142679 for ; Thu, 20 Sep 2012 17:37:45 -0500 Received: from ipmail06.adl2.internode.on.net (ipmail06.adl2.internode.on.net [150.101.137.129]) by cuda.sgi.com with ESMTP id NMbxkNtwwFhV4LHs for ; Thu, 20 Sep 2012 15:38:56 -0700 (PDT) Date: Fri, 21 Sep 2012 08:38:52 +1000 From: Dave Chinner Subject: Re: Questions on RAID alignment Message-ID: <20120920223852.GI31501@dastard> References: <505AF9EA.7030603@shiftmail.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <505AF9EA.7030603@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 Thu, Sep 20, 2012 at 01:11:38PM +0200, Spelic wrote: > Hello list > a few questions > > 1- Does XFS support alignment to concatenation RAIDs (e.g. linear > over raid1) similarly to striped ones? No. It's being considered and I know how to do it, but it's lower priority than other stuff I'm working on at the moment. > I am guessing probably su and > sw should not be specified and the agcount should be multiple of the > number of the concatenated devices, is that correct? If you are concatenating RAID0/5/6, then you shoul duse su/sw as per the alignment of the volumes being concatenated. > 2- Can mkfs parameters be altered after creation, e.g. after growing > a RAID and then growing the XFS fs, can I also alter su, sw, agcount > somehow? You can alter su/sw as a mount option if the filesystem was made with them initially. > 3- I seem to remember there was an xattr that one could attach to > /home (if /home was under XFS) so that every user (subdir of /home) > would get a different AG in a different RAID device. I cannot find > that information anymore on the internet; could you refresh my mind? Nothing of the sort. if you are using the inode64 allocator, then each new directory is placed i a different AG. That's as good as it gets right now. Cheers, Dave. -- Dave Chinner david@fromorbit.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs