From mboxrd@z Thu Jan 1 00:00:00 1970 From: Neil Brown Subject: Re: /proc/mdstat showing a device missing from array Date: Mon, 14 May 2007 11:07:06 +1000 Message-ID: <17991.46650.304434.640289@notabene.brown> References: <1179081234.46475a12d46ba@mail.2inches.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: message from evoltech@2inches.com on Sunday May 13 Sender: linux-raid-owner@vger.kernel.org To: evoltech@2inches.com Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids On Sunday May 13, evoltech@2inches.com wrote: > > > Hello all, > > I just set up a new raid 5 array of 4 750G disks and am having a strange > experience where /proc/mdstat is showing that one device is missing from the > array. The output from a "--detail" shows that there is some unnamed device > that has been removed from the array and I don't understand why or how to fix > it. Can someone please shed some light? A raid5 is always created with one missing device and one spare. This is because recovery onto a spare is faster than resync of a brand new array. The real problem here is that recovery has not started. If you mdadm -S /dev/md2 mdadm -A /dev/md2 /dev/sd[def] mdadm /dev/md2 -a /dev/sdg it will start recovery. This bug was fixed in mdadm-2.5.2 NeilBrown