From mboxrd@z Thu Jan 1 00:00:00 1970 From: Goswin von Brederlow Subject: Re: Change Chunk Size on Array? Date: Wed, 13 May 2009 09:33:38 +0200 Message-ID: <878wl1ihil.fsf@frosties.localdomain> References: <16137381.post@talk.nabble.com> <23514897.post@talk.nabble.com> <18954.20603.952706.467047@notabene.brown> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: In-Reply-To: <18954.20603.952706.467047@notabene.brown> (Neil Brown's message of "Wed, 13 May 2009 14:45:47 +1000") Sender: linux-raid-owner@vger.kernel.org To: Neil Brown Cc: SandeepKsinha , linux-raid@vger.kernel.org List-Id: linux-raid.ids Neil Brown writes: > Online changing of chunk size for raid5 is very close to being > implemented. > All the kernel side support will be in 2.6.30. > I just need to spend some time getting mdadm to make it work. > Because data is being rearranged in-place, and because you don't want > to lose everything if your systems crashes, mdadm will have to work in > tandem with the kernel making a backup copy of a section of the array, > allowing the kernel to reshape that section, and then moving on to the > next section. It will be slow, but it will be reliable. > > NeilBrown Shouldn't mdadm create a file and pass the FD to the kernel or a loopback device and pass the major/minor and the kernel then moves data there itself? Seems like a bad idea to pass all the data of the raid to userspace just so it can be passed back to the kernel again. MfG Goswin