From mboxrd@z Thu Jan 1 00:00:00 1970 From: NeilBrown Subject: Re: GPT Table broken on a Raid1 Date: Sun, 23 Sep 2012 07:58:43 +1000 Message-ID: <20120923075843.42ec8efb@notabene.brown> References: <4961154.0TR9MeFlIq@techz> <2627519.Y2VdWh5VBI@techz> <1BDFB79A-E375-47F2-8EDF-8F51D8774651@colorremedies.com> <1361158.MkTZ6QR6cp@techz> <3EC7177F-9973-4D2E-988B-7020298E1727@colorremedies.com> <505DD9E2.7090908@anonymous.org.uk> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=PGP-SHA1; boundary="Sig_/V1a=uu2dR/YPowO5WgdOwxk"; protocol="application/pgp-signature" Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: Chris Murphy Cc: Linux RAID List-Id: linux-raid.ids --Sig_/V1a=uu2dR/YPowO5WgdOwxk Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable On Sat, 22 Sep 2012 12:45:39 -0600 Chris Murphy wrote: >=20 > On Sep 22, 2012, at 9:31 AM, John Robinson wrote: >=20 > >=20 > > I don't think there's anything wrong here. > >=20 > > The kernel sees the whole discs, sda and sdb, and complains that the GP= T partition table looks wrong becase the second copy isn't at the end of th= e discs. That's correct, at the end of the raw discs is the IMSM metadata. >=20 > OK so sda and sdb shouldn't have been partitioned in the first place, is = what that tells me. >=20 >=20 > > Don't try to change the partition tables on /dev/sda and sdb or you wil= l damage the IMSM metadata. >=20 > Sounds like either imsm metadata is either not well designed for GPT, or = it was intended to be placed on an unpartitioned disk in the first place.=20 IMSM metadata is definitely intended to be placed on an un-partitioned disk. The only real point of IMSM is to provide interoperability with other implementations, whether the one for Windows (allowing dual-boot) or the one in the bios (allowing boot-from-RAID5 etc). Those other implementations use IMSM on the whole device, so it would be pointless using mdadm/IMSM on partitions. Note that I haven't really been following this thread, so I might have miss= ed the point. I'm really just responding to that last sentence. NeilBrown --Sig_/V1a=uu2dR/YPowO5WgdOwxk Content-Type: application/pgp-signature; name=signature.asc Content-Disposition: attachment; filename=signature.asc -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.18 (GNU/Linux) iQIVAwUBUF40kznsnt1WYoG5AQLTpxAAwzZOUzG7ch11bM4iDofoh8THFRCjOf34 EAZUdshcBEMb25nq/vx8XZWf+hB4IJJU5DN1FIlW7EmfknuN7ep1YBsxMCkz7MKO Dw+eO9DLettFo0bjZFTkpqQy6eWeHpf3RMKIa/SoxRQg0S5q3msbUcrx34ceDmGG m5F9O58YPlSRkkmrvT/0Vrd29LfkB4MwPG0BI0nl+NT/2E2HTuDbgNsqgpBCZqBF vvRJbijhL1OkhBvAuQY2Dm9VM0YSrfHe9LIjUbyKr+6WYpwkMugbgnPhrBvki1s6 tD2MFtPphbiiG+pMHtxHyyCQmLkDY1DGxlaZb+Xkq11psDiaJNs/XB7g+byeNABi 4t/lOhveqqZt4c6cefGqEY30jAmBO6xuXwIkIrzsTEFHxf30Yako4OFi8D+pr5q6 Y5wQb3cl/Q5HNaryZvZbbeAOFvzp7mhueXPnTP7hjc5EIpV7qk/8npTVi3JyLe8x ieYRYR9lNcJLADQguc5zyMt7YYZRryr9drQXXnXBge2U2JaAYMmlw/lApbp/pz3n W0o4lgO9BMNOMm5h2BNXQxg7Sm7cAVCahxDTZc9DUvrqw78lAOkDSig44MJYCvVP m/vfzrRO7fnEOMi1rpiP0Lr29/pykXmoM+bwIfRtEsMyr4e8AvR7kAu7frguqu1r XHYeo7TSnrs= =7uC7 -----END PGP SIGNATURE----- --Sig_/V1a=uu2dR/YPowO5WgdOwxk--