From mboxrd@z Thu Jan 1 00:00:00 1970 From: Heinz Mauelshagen Subject: Re: [PATCH 0 of 10] LVM: Mirrored log support Date: Fri, 09 Oct 2009 18:07:17 +0200 Message-ID: <1255104437.20671.1.camel@o> References: <1255036474.12319.16.camel@hydrogen.msp.redhat.com> Reply-To: heinzm@redhat.com, device-mapper development Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1255036474.12319.16.camel@hydrogen.msp.redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com To: device-mapper development List-Id: dm-devel.ids Hi Jon, shouldn't these rather go to lvm-devel ? Heinz On Thu, 2009-10-08 at 16:14 -0500, Jonathan Brassow wrote: > I spent the last few days looking over the mirror allocation code. I > wanted to understand why 'log_count' was being treated generically in > most places... as if the idea of mirrored logs were already thought of. > I mostly discovered that it was possible to push what looked like > incomplete code towards completion. The following patches represent > where I would like the mirrored log support to start from. > > These patches are a replacement to the proposed patches - a fresh start. > They address a couple problems that I saw with the old patches: 1) > Allocation policies are respected and behave the same as today for other > log types. > 2) The on-disk layout of the previous version - when given only two > disks to allocate from - would put the log on the front of one device > and the back of another. This virtually ensures a performance hit. > These patches put the logs in the same place WRT the images. > 3) The new patches reduce parameter bloat. I think the previous patches > required the extra parameters because they were using functions deep in > the code that were from higher levels... adding parameters and > "spaghettifying" the code. > > These patches should be considered a starting point. While 'lvcreate' > works, 'lvconvert' does not handle all transitions. In fact, > 'lvconvert' will only handle 'core' -> 'disk/redundant' and > 'disk/redundant' -> 'core'. It will not handle 'disk' <-> 'redundant'. > > brassow > > -- > dm-devel mailing list > dm-devel@redhat.com > https://www.redhat.com/mailman/listinfo/dm-devel