From mboxrd@z Thu Jan 1 00:00:00 1970 From: Neil Brown Subject: Re: mdadm: failed devices become spares! Date: Tue, 18 May 2010 12:06:37 +1000 Message-ID: <20100518120637.24d875c9@notabene.brown> References: <9D.D3.23029.CDD40FB4@cdptpa-omtalb.mail.rr.com> <201005172010.36157.pierre@vigneras.name> <20100518113016.1981a08c@notabene.brown> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <20100518113016.1981a08c@notabene.brown> Sender: linux-raid-owner@vger.kernel.org To: Neil Brown Cc: Pierre =?UTF-8?B?VmlnbsOpcmFz?= , Leslie Rhorer , linux-raid@vger.kernel.org List-Id: linux-raid.ids On Tue, 18 May 2010 11:30:16 +1000 Neil Brown wrote: > On Mon, 17 May 2010 20:10:36 +0200 > Pierre Vign=C3=A9ras wrote: >=20 > > Did I miss something, or is there something really strange happenin= g there? >=20 > Something strange... > I cannot explain the 'SpareActive' messages. Actually I can explain that I think. When a device fails it gets marked as faulty, then as soon as there is = no more pending IO it gets moved out of the array. "mdadm -D" will show i= t with a larger 'Number' and a 'RaidDevice' of '-'. Normally these happen almost as a single operation, though a lot of pen= ding IO can slow it down. "mdadm --monitor" identified devices based on 'Number', so it would nor= mally see a working device disappear - which is reported a a failure, and a 'faulty/spare' device appear, which it ignores. However if --monitor gets to check the array between the above to event= s, it will first see that the working drive is now faulty, so it reports a fa= ilure, and then see that the faulty device isn't faulty any more and in fact i= sn't even there. The "isn't event there" bit doesn't register and it treats= it as 'SpareActive'. I should fix that. So I'm quite sure now that your devices didn't really become spares unt= il you removed and added them, which is exactly they way to turn failed device= s into spares. NeilBrown -- To unsubscribe from this list: send the line "unsubscribe linux-raid" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html