From mboxrd@z Thu Jan 1 00:00:00 1970 From: Neil Brown Subject: Re: Simple Raid-1 setup question Date: Sat, 14 Nov 2009 09:24:14 +1100 Message-ID: <19197.56462.814164.773415@notabene.brown> References: <4AFDC2DD.9040002@lamer.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: message from Kurt Newman on Friday November 13 Sender: linux-raid-owner@vger.kernel.org To: Kurt Newman Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids On Friday November 13, kurt@lamer.org wrote: > My questions are as follows: > > 1) If you're creating a completely new array (e.g. raid-1) on new > partitions that aren't formatted, do you still have to sync? I'm having > difficulty finding information on why and when a sync is needed. I was > under the impression a sync is only needed when there's existing > information on one or more of the drives. You don't need to for RAID1 - you do for RAID5. If you don't with RAID1, then the first time you run a 'check' to 'scrub' the array, it might report lots of differences in mismatch_cnt. > > 2) If there used to be information on each device, but has since been > repartitioned, so that new partitions and a raid device can be > created... is there any way to prevent mdadm from asking if you really > want to create the array? Using `--force' doesn't seem to help. use -R or --run if you are really sure. NeilBrown > > mdadm: /dev/sda1 appears to contain an ext2fs file system > size=1464840K mtime=Fri Nov 13:04:09 2009 > mdadm: /dev/sdb1 appears to contain an ext2fs file system > size=1464840K mtime=Fri Nov 13:04:09 2009 > Continue creating array? > > As a side note, there really isn't an existing ext3 fs on it, but there > used to be. To re-use the device, I issued the following commands: > > parted -s /dev/sda mklabel msdos > > parted -s /dev/sda mkpart primary ext3 0 1500 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-raid" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html