From mboxrd@z Thu Jan 1 00:00:00 1970 From: Josef Bacik Subject: Re: Offline Deduplication for Btrfs Date: Wed, 5 Jan 2011 15:28:54 -0500 Message-ID: <20110105202854.GE2562@localhost.localdomain> References: <1294245410-4739-1-git-send-email-josef@redhat.com> <4D24AD92.4070107@bobich.net> <201101051941.13268.diegocg@gmail.com> <20110105190139.GA32671@bludgeon.org> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Cc: Diego Calleja , Gordan Bobic , BTRFS MAILING LIST To: Ray Van Dolson Return-path: In-Reply-To: <20110105190139.GA32671@bludgeon.org> List-ID: On Wed, Jan 05, 2011 at 11:01:41AM -0800, Ray Van Dolson wrote: > 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 doin= g the=20 > > > hashing is in no way reduced. > >=20 > > But there are people who might want to avoid temporally the extra c= ost > > 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, = and > > the best choice is probably implement both. >=20 > 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 syste= m > data continues to be available, or a process that needs exclusive > access ot the blocks to do its job? >=20 Yeah its just a post-process thing, you run it when you care to run it = and it doesn't make anything unavailable. Thanks, Josef -- 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