From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx1.redhat.com (mx1.redhat.com [172.16.48.31]) by int-mx1.corp.redhat.com (8.13.1/8.13.1) with ESMTP id l77LiqjQ002073 for ; Tue, 7 Aug 2007 17:44:52 -0400 Received: from marge.panici.net (marge.panici.net [207.234.208.94]) by mx1.redhat.com (8.13.1/8.13.1) with ESMTP id l77Lin0R018212 for ; Tue, 7 Aug 2007 17:44:49 -0400 Received: from marge.panici.net (localhost.localdomain [127.0.0.1]) by marge.panici.net (8.13.8/8.13.8/Debian-3) with ESMTP id l77Ling1004210 for ; Tue, 7 Aug 2007 21:44:49 GMT Received: (from paddy@localhost) by marge.panici.net (8.13.8/8.13.8/Submit) id l77LimNC004209 for linux-lvm@redhat.com; Tue, 7 Aug 2007 21:44:48 GMT Date: Tue, 7 Aug 2007 21:44:48 +0000 From: paddy@panici.net Subject: Re: [linux-lvm] Best practice: metadata backup Message-ID: <20070807214448.GD3732@localhost.localdomain> References: <20070807190153.GV2064@agk.fab.redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20070807190153.GV2064@agk.fab.redhat.com> Reply-To: LVM general discussion and development List-Id: LVM general discussion and development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , List-Id: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-lvm@redhat.com On Tue, Aug 07, 2007 at 08:01:53PM +0100, Alasdair G Kergon wrote: > > AIX treats the boot LV specially, and ensures > > that its PEs are contiguous at the beginning of the disk(s). > > Nothing is stopping a linux installer doing that today: > --alloc contiguous and specify the extents. (its been a long time but) last time I looked there was no facility to flag an LV in a manner that would accord it treatment from the various utilities appropriate to it's status as a boot volume (such as, for example, not moving about). Of course, when I looked there wasn't any functionality in the utilities that did anything to worry about :-) (but user-space code is easier written than on-disk representations are changed) (unless its already been done ...) by the time anyone gets around to it, the various bios limitation of PCs, etc will all be just a memory. > But if grub supports LVM2 properly (add a trivial mapping layer from LV > extents to physical sectors, then populate it from the LVM2 metadata > across an agreed interface from a library maintained as part of the lvm2 > package) it won't require anything like that of course - the hardest > problem I think is actually for it to identify the right disks to use. (and yet strangely we all manage to boot ... !?!? ) ... or everyone uses a boot-loader that reads filesystems, and they all learn to read LVM too :-) Regards, Paddy