From mboxrd@z Thu Jan 1 00:00:00 1970 From: Goswin von Brederlow Subject: Re: Subject: [001/002 ] raid0 reshape Date: Mon, 25 May 2009 14:19:50 +0200 Message-ID: <87r5ydqsrd.fsf@frosties.localdomain> References: <1241300764.5607.36.camel@raz> <18965.16276.485692.812516@notabene.brown> <87f94c370905211220n4e686a30ke452a56a2690d22b@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: In-Reply-To: <87f94c370905211220n4e686a30ke452a56a2690d22b@mail.gmail.com> (Greg Freemyer's message of "Thu, 21 May 2009 15:20:42 -0400") Sender: linux-raid-owner@vger.kernel.org To: Greg Freemyer Cc: Neil Brown , Dan Williams , raz ben yehuda , linux-raid@vger.kernel.org, Jacek Danecki , "Labun, Marcin" List-Id: linux-raid.ids Greg Freemyer writes: > ==> What I mean by raid equivalent levels > > More and more arrays allow the user to simply say "give me a 100 GB > logical volume with Raid 5 equivalent protection. The array then > looks at the drives it has available and puts together the necessary > pieces. As drives are added, removed it moves the data around under > its own control, but maintains the raid equivalent protection. > > Especially when working with dozens of drives and lots of logical > volumes it makes life much easier. Admittedly it may come at a cost > of not being able to specify raid levels with the specificity that > mdraid currently allows. > > ==> > > The reason I ask if this is the goal is that doing so may factor into > decisions about how reshaping is implemented. > > Greg That really seems to scream for LVM to support more raid levels. It already has linear, raid0 and raid1 support (although I have no idea how device mapper raid1 compares to md raid1). Those should be fleshed out more and also support raid 4/5/6 for what you ask. MfG Goswin