From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Robinson Subject: Re: RAID5 reconstruction ? Date: Sat, 30 May 2009 17:30:24 +0100 Message-ID: <4A215F20.8060901@anonymous.org.uk> References: <37d33d830905292244w685499b3h391aa2ca7a5b1ad@mail.gmail.com> <4A213612.7080206@anonymous.org.uk> <4A213D6B.8040501@usherbrooke.ca> <4A2154C5.6050500@anonymous.org.uk> <4A215BD0.3070901@usherbrooke.ca> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <4A215BD0.3070901@usherbrooke.ca> Sender: linux-raid-owner@vger.kernel.org To: Maxime Boissonneault Cc: Linux RAID List-Id: linux-raid.ids On 30/05/2009 17:16, Maxime Boissonneault wrote: > John Robinson a =E9crit : >> On 30/05/2009 15:06, Maxime Boissonneault wrote: >>> I don't know how it goes for Linux, but hasn't ZFS been developped=20 >>> exactly for that purpose ? From what I understand, ZFS manage both=20 >>> the file system and the RAID features at once. Therefore, the "raid= "=20 >>> part knows where are the files and the filesystem knows about the=20 >>> raid. Reconstruction is then done intelligently (not reconstructing= =20 >>> unused space). >> >> Yes, ZFS can do this, but ext4 and md could do it too, and probably=20 >> will at some point. I prefer separating the layers, then I can switc= h=20 >> one and not the other, e.g. start using a hardware RAID controller=20 >> instead of md. >> > Chances are that the hardware controler would not be compatible with=20 > mdadm and you would have to backup and copy your data anyway. Sure, but I can keep my filesystem, which I've chosen for whatever=20 filesystem features it has, rather than having chosen it because it doe= s=20 RAID itself. It would be nice if RAID controllers and md used the same metadata,=20 though, wouldn't it, so we could swap discs between controllers and=20 everything would Just Work? Umm, do any RAID controllers support SNIA=20 DDF? I think md does (or soon will)... Cheers, John. -- To unsubscribe from this list: send the line "unsubscribe linux-raid" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html