From mboxrd@z Thu Jan 1 00:00:00 1970 From: NeilBrown Subject: Re: raid device gone underneath array Date: Mon, 22 Oct 2012 09:19:21 +1100 Message-ID: <20121022091921.33f78a22@notabene.brown> References: Mime-Version: 1.0 Content-Type: multipart/signed; micalg=PGP-SHA1; boundary="Sig_/ZNR8WAN15bjS=Q3_vE9VeCz"; protocol="application/pgp-signature" Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: Marcus Sorensen Cc: linux-raid List-Id: linux-raid.ids --Sig_/ZNR8WAN15bjS=Q3_vE9VeCz Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable On Thu, 18 Oct 2012 18:01:34 -0600 Marcus Sorensen wrote: > I've been using software raid to mirror two devices, and recently one > of the drives went AWOL. >=20 > md1 : active raid1 sdm[0] sdc[1](F) > 12884900728 blocks super 1.2 [2/1] [U_] > bitmap: 1/96 pages [4KB], 65536KB chunk >=20 > However, md1 froze, and in looking at the logs I saw this: >=20 > Oct 18 17:47:48 sys kernel: md: cannot remove active disk sdc from md1 ... > Oct 18 17:47:48 sys kernel: md: cannot remove active disk sdc from md1 ... >=20 > [root(marcus)@sanmirror3-01 ~]# mdadm --manage /dev/md1 --remove /dev/sdc > mdadm: cannot find /dev/sdc: No such file or directory >=20 > /dev/sdc was already gone! The /sys/block was already removed, no > reference to it in /proc/scsi/scsi. So md1 was destined to sit there > forever. So I rebooted and started up the degraded array. These messages imply that 'sdc' was sent a request and no reply has been received. Until the count of pending requests hits zero, md cannot completely release sdc, and if it was a write - cannot reply to the request that it received from a files system. When a device fails or disappears the driver should ensure that all pending requests fail - and return that failure status. md depends on this. So - assuming this status continued for more than a minute - it looks like a bug with the driver for 'sdc'. NeilBrown >=20 > Using kernel 3.6.2 from kernel.org > -- > To unsubscribe from this list: send the line "unsubscribe linux-raid" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html --Sig_/ZNR8WAN15bjS=Q3_vE9VeCz Content-Type: application/pgp-signature; name=signature.asc Content-Disposition: attachment; filename=signature.asc -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.18 (GNU/Linux) iQIVAwUBUIR06Tnsnt1WYoG5AQIy0g//UtqqZQf1cINWTQx1rS182VwHipMh6wDo /8Yr16TsB33tmmze+ckokmWmgVGg+3eaIQh3j8iBD1itPsjMTpcx8zNkkuQG9S90 k9RWPw/iVNz5R2lm7rlEc0Wu3tF6ibWVXbMQEMkh1TD3gz1wqQu5af764SpjN3eT f5t1wTech3RTJ3wuK0XlVuo1Hi10R6FnvacptCT1gLSvWfoQ/69AG1xTaGf6Fqxq Z3QEX8ODvt4wWiN9BLvjfrKq02jyaiqvEOJDIhrEm42V9O5UKipJ6ttt4k1vMwA2 BoDGu2OdTuWCMj6p0RXibgiWlSOJmMz02awD8xxkJ8pssFxbnoU5giPnTkScvwJX 3BtWM9dS917YgMvWfKHJoaowAQsJDhgGq9aWi7DKsf+xcBRqAZb07j2AqM2zwmfD iiqLcYXnIyla17i+g49RIn9JzQe4/H2Zbhgvgzzngcn3b5JXP3Tijyyf98cooo3a 0pNfe6NAiuymQDtSz/B1UJGkJbuCVyewB7UqbCDYZm1xoPv1AuBCTEVaVHGYEfUz UyDZN6YSGnxxqb9yeOcbfxOmAPts4w3ocwVx7yX76REgwTTXY4ejs92RpE9NAdu+ MTO+OyTGgPXR7UuhbGWgTOQdx/R2qnv8h2V+rJJ4bg13BKoZJXhidxMQ97JGZVW7 9C1sTnA6STc= =VP6G -----END PGP SIGNATURE----- --Sig_/ZNR8WAN15bjS=Q3_vE9VeCz--