From mboxrd@z Thu Jan 1 00:00:00 1970 From: Goswin von Brederlow Subject: Re: Requesting replace mode for changing a disk Date: Wed, 13 May 2009 09:28:24 +0200 Message-ID: <87d4adihrb.fsf@frosties.localdomain> References: <4A060CBE.9090308@tmr.com> <20090513012112681.IEFQ19662@cdptpa-omta02.mail.rr.com> <18954.19719.172893.761454@notabene.brown> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: In-Reply-To: <18954.19719.172893.761454@notabene.brown> (Neil Brown's message of "Wed, 13 May 2009 14:31:03 +1000") Sender: linux-raid-owner@vger.kernel.org To: Neil Brown Cc: lrhorer@satx.rr.com, 'Linux RAID' List-Id: linux-raid.ids Neil Brown writes: > On Tuesday May 12, lrhorer@satx.rr.com wrote: >> >> But doesn't creating the array with the drive wipe the contents? If so, it >> doesn't seem to me this provides much redundancy. > > No. Creating an array does not wipe the contents. > It might cause a resync which will copy contents from one drive to the > other and I don't promise which one. > However if you: > > mdadm -C /dev/md0 --level 1 -n 2 /dev/foo missing > mdadm /dev/md0 --add /dev/bar > > then the contents on /dev/foo will not be changed (except for a few K > at the end for the metadata) and then all of foo will be copied to > bar. > > NeilBrown But as the disk is already part of a raid those few K at the end would be the critical meta data of the original raid. This only works with a raid without metatada. MfG Goswin