From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay1.corp.sgi.com [137.38.102.111]) by oss.sgi.com (Postfix) with ESMTP id 8E11D7CA3 for ; Thu, 11 Aug 2016 04:26:40 -0500 (CDT) Received: from cuda.sgi.com (cuda1.sgi.com [192.48.157.11]) by relay1.corp.sgi.com (Postfix) with ESMTP id 2C9938F8035 for ; Thu, 11 Aug 2016 02:26:39 -0700 (PDT) Received: from smtp2.cc.ic.ac.uk (smtp2.cc.ic.ac.uk [146.179.32.42]) by cuda.sgi.com with ESMTP id tZk8BX52yhhFGflr (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO) for ; Thu, 11 Aug 2016 02:26:37 -0700 (PDT) Date: Thu, 11 Aug 2016 10:26:04 +0100 From: Wei Lin Subject: Re: Question on migrating data between PVs in xfs Message-ID: <20160811092604.GA4615@ic> References: <20160809145046.GB5583@ic> <20160809223503.GJ19025@dastard> <20160810092313.GA16193@ic> <20160810105639.GR16044@dastard> <20160810183132.0b9ae8e4@harpe.intellique.com> <20160810215149.GM19025@dastard> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20160810215149.GM19025@dastard> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com To: Dave Chinner Cc: xfs@oss.sgi.com, Wei Lin On 16-08-11 07:51:49, Dave Chinner wrote: > On Wed, Aug 10, 2016 at 06:31:32PM +0200, Emmanuel Florac wrote: > > Le Wed, 10 Aug 2016 20:56:39 +1000 > > Dave Chinner =E9crivait: > > = > > > Have you lookd at using dm-cache instead of modifying the > > > filesystem? > > > = > > = > > Or bcache, fcache, or EnhanceIO. So far from my own testing bcache is > > significantly faster and dm-cache by far the slowest of the bunch, but > > bcache needs some more loving (his main developer is busy writing > > some new tiered, caching filesystem instead). > = > Yeah, the problem with bcache is that it is effectively an orphaned > driver. If there are obvious and reproducable performance > differentials between bcache and dm-cache, you should bring them to > the attention of the dm developers to see if they can fix them... > = > Cheers, > = > Dave. > -- = > Dave Chinner > david@fromorbit.com Software like dm-cache and bcache seem to use SSDs merely as caches instead of aggregating the capacity of all devices. However I just found aufs and overlayfs, which conceptually suit the purpose better. Cheers, -- = Wei Lin _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs