From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [dm-devel] [PATCH][RFC] dm: Do not open log and cow device read-write for read-only mappings Date: Wed, 16 Feb 2011 09:39:51 +0100 Message-ID: <20110216083951.GC19830@htj.dyndns.org> References: <4D5A6EF4.3030905@redhat.com> <20110215124629.GF5825@agk-dp.fab.redhat.com> <20110215152033.GK3160@htj.dyndns.org> <20110215154625.GG5825@agk-dp.fab.redhat.com> <20110215155018.GM3160@htj.dyndns.org> <4D5AA45C.7050600@redhat.com> <20110215161228.GN3160@htj.dyndns.org> <4D5AAB8F.50901@redhat.com> <20110215164128.GQ3160@htj.dyndns.org> <4D5AB0C5.9030304@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <4D5AB0C5.9030304@redhat.com> Sender: linux-kernel-owner@vger.kernel.org To: Milan Broz Cc: Alasdair G Kergon , Neil Brown , device-mapper development , Jens Axboe , Tao Ma , linux-kernel@vger.kernel.org List-Id: dm-devel.ids On Tue, Feb 15, 2011 at 05:58:45PM +0100, Milan Broz wrote: > # blockdev --setrw /dev/sd[bcde] > # mdadm -A /dev/md0 /dev/sd[bcde] > mdadm: /dev/md0 has been started with 4 drives. > # mdadm --stop /dev/md0 > mdadm: stopped /dev/md0 > # blockdev --setro /dev/sd[bcde] > # mdadm -A /dev/md0 /dev/sd[bcde] > mdadm: cannot re-read metadata from /dev/sdb - aborting > > Works on 2.6.36. Isn't failing to assemble rw array from ro devices the expected behavior? I think I'd want that to fail. Neil, what do you think? -- tejun