From mboxrd@z Thu Jan 1 00:00:00 1970 From: Neil Brown Subject: Re: RAID 0 md device still active after pulled drive Date: Mon, 20 Oct 2008 11:35:33 +1100 Message-ID: <18683.53845.702858.972766@notabene.brown> References: <8CAFECFAC51849A-1CD4-454@FWM-D03.sysops.aol.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: message from thomas62186218@aol.com on Friday October 17 Sender: linux-raid-owner@vger.kernel.org To: thomas62186218@aol.com Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids On Friday October 17, thomas62186218@aol.com wrote: > Hi All, > > I have run into a most unusual behavior, where mdadm reports a RAID 0 > array that is missing a drive as "Active". Not unusual at all. mdadm has always behaved this way. There is nothing that 'md' can ever do about a failed drive in a raid0, so it doesn't bother doing anything. At all. As far as md is concerned, the drive is still an active part of the array. It will still try to send appropriate IO requests to that device. If they fail (e.g. because the device doesn't actually exist), then md will send that error message back. > > > Conclusion: Why does mdadm report a drive failure on RAID 0 but not > make the md device as Inactive or otherwise failed? where exactly did "mdadm report a drive failure" on the RAID0 ?? As always, if you think the documentation could be improved to reduce the chance of this sort of confusion, or if the output of mdadm could make something more clear, I am open to constructive suggestions (and patches). NeilBrown