From mboxrd@z Thu Jan 1 00:00:00 1970 From: NeilBrown Subject: Re: Multiple arrays out of devices belonging to single array Date: Fri, 5 Dec 2014 22:17:38 +1100 Message-ID: <20141205221738.79d2f8d6@notabene.brown> References: <54817A83.6020000@msgid.tls.msk.ru> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; boundary="Sig_/eJGJKn4.orq4KwZW57cJo4e"; protocol="application/pgp-signature" Return-path: In-Reply-To: <54817A83.6020000@msgid.tls.msk.ru> Sender: linux-raid-owner@vger.kernel.org To: Michael Tokarev Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids --Sig_/eJGJKn4.orq4KwZW57cJo4e Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable On Fri, 05 Dec 2014 12:27:31 +0300 Michael Tokarev wrote: > Hello. >=20 > We in Debian have 2 rather similar bugreports which are somewhat old: > http://bugs.debian.org/599352 > http://bugs.debian.org/694513 > Last bugreport is against mdadm-3.2.5, so not THAT old. >=20 > Basically, it smells like there's a possibility for mdadm to assemble > more than one (degraded) array out of components of the same array. >=20 > So I wonder if mdadm or kernel have some protection of this situation > from happening. Something like looking at already active/assembled > devices to see if the same UUID is already used before trying to > assemble another array. >=20 > It might be better done in kernel because this way the process might > be freee from races when two mdadm instances tries to do the work in > parallel. >=20 > Are these bugs for real? Certainly are. Fix in 3.3 I think. commit 0431869cec4c673309d9aa30a2df4b778bc0bd24 Author: NeilBrown Date: Wed Oct 10 18:27:32 2012 +1100 Fix up interactions between --assemble and --incremental is one part of the fix. I cannot quickly find another patch which obviously relates to the symptoms described, but my vague memories suggest there was more than one patch. NeilBrown --Sig_/eJGJKn4.orq4KwZW57cJo4e Content-Type: application/pgp-signature Content-Description: OpenPGP digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIVAwUBVIGUUjnsnt1WYoG5AQK+cg//ej3R0ZsxNIURzIyX5tfB98SEXELBXcht l3HI4oGYxiDa9ZfaGXkmAQKSaCjvaOCPfB+1YJR9c4n9u1YUmodSu4eIyotIKD2R wk/dfuTKUuD7ibwUrEn+UnLMyzR6MJiSOwje9e7Apq+sCUbU2guNbo4OK8xrKr64 ierKRHstqD8oKEk2ZYaVhnQ3z4+WUPy8LKlXi7b6Mxs+wpgfN/7DAZ310qC3ZXjN xqMKf++BZK9aJT5CXhgH2k5HKCojkYmkjbAw5hUINLD/hU5Iy0cdFrW6b6wiIu0X 6AZw7BVA+vQcGGqn6RL2CMIvyeXaf+qVQszTh8ePEOn2JG59CzFyvkyFS9kzyQbr W4qPI8+UILMjK1S9Rsg4u28N7xalUaaeHBLlNwT/rFF4UA8qfgPrhNMmItKqMvIq zo4BB54GKvT7a/7AgDiG8Sz4Ee7xKiG1B+2Wh2OmxyrsHj6mr+0TTX4tLSgNDxnH bOTEkxrNj4lnOJG0dBNq3j4rmgjZWv1J4rMhkixdg6D86r0liWTD4ofoorob2U/k Xs7es4dN8jAsJQq1HSlGhvx+gXhBuWklkkz17+BdWbEeo6PpAI1JsgbAX8cUmcQ7 WPI/WNIRtXbe6FFTV09xBjhAuZvmMaXnXe56sZuwVZEftH1SYU+Inm5QLdWTBotk OYXuVUsH5Cc= =IUnd -----END PGP SIGNATURE----- --Sig_/eJGJKn4.orq4KwZW57cJo4e--