From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ray Van Dolson Subject: Re: Offline Deduplication for Btrfs Date: Wed, 5 Jan 2011 11:01:41 -0800 Message-ID: <20110105190139.GA32671@bludgeon.org> References: <1294245410-4739-1-git-send-email-josef@redhat.com> <4D24AD92.4070107@bobich.net> <201101051941.13268.diegocg@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Cc: Gordan Bobic , BTRFS MAILING LIST To: Diego Calleja Return-path: In-Reply-To: <201101051941.13268.diegocg@gmail.com> List-ID: On Wed, Jan 05, 2011 at 07:41:13PM +0100, Diego Calleja wrote: > On Mi=E9rcoles, 5 de Enero de 2011 18:42:42 Gordan Bobic escribi=F3: > > So by doing the hash indexing offline, the total amount of disk I/O= =20 > > required effectively doubles, and the amount of CPU spent on doing = the=20 > > hashing is in no way reduced. >=20 > But there are people who might want to avoid temporally the extra cos= t > of online dedup, and do it offline when the server load is smaller. >=20 > In my opinion, both online and offline dedup have valid use cases, an= d > the best choice is probably implement both. Question from an end-user. When we say "offline" deduplication, are we talking about post-process deduplication (a la what Data ONTAP does with their SIS implementation) during which the underlying file system data continues to be available, or a process that needs exclusive access ot the blocks to do its job? Ray -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" = in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html