From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bill Davidsen Subject: Re: Spare drive won't spin down Date: Mon, 10 May 2010 12:59:33 -0400 Message-ID: <4BE83B75.8050709@tmr.com> References: <922812.29139.qm@web31703.mail.mud.yahoo.com> <20100507162034.1370d645@notabene.brown> <717013.48748.qm@web31703.mail.mud.yahoo.com> <20100507194704.3ffcf17e@notabene.brown> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20100507194704.3ffcf17e@notabene.brown> Sender: linux-raid-owner@vger.kernel.org To: Neil Brown Cc: Joe Bryant , linux-raid@vger.kernel.org List-Id: linux-raid.ids Neil Brown wrote: > On Fri, 7 May 2010 00:40:40 -0700 (PDT) > Joe Bryant wrote: > > >>> I'll see about fixing that. >>> >>> Recreate the array with "--metadata 1.0" or "--metadata 1.2" and it should work better. >>> >> That's great, thanks very much. >> >> > > It turns out it is a bit more subtle than that, though that approach may work > for you. > If you make an odd number of changes to the metadata, it will switch from > doing what you want, to not. > e.g. if /dev/foo is your spare device, then > > mdadm /dev/md0 -f /dev/foo > mdadm /dev/md0 -r /dev/foo > mdadm /dev/md0 -a /dev/foo > > will switch between working and not working. v0.90 metadata starts out not > working. v1.x start out working. > So we can assume that the little dance steps above will make 1.x misbehave in the same way? Could you explain (point to an explanation) why this whole odd/even thing exists? -- Bill Davidsen "We can't solve today's problems by using the same thinking we used in creating them." - Einstein