From mboxrd@z Thu Jan 1 00:00:00 1970 From: NeilBrown Subject: Re: mdadm -E won't examine loop back device, works ok on source disk Date: Mon, 23 Apr 2012 15:04:54 +1000 Message-ID: <20120423150454.1b46d01c@notabene.brown> References: <20120423075816.6d21afe8@notabene.brown> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=PGP-SHA1; boundary="Sig_/WVj2zfRvk9=Aj1UtVyKa.LB"; protocol="application/pgp-signature" Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: Veedar Hokstadt Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids --Sig_/WVj2zfRvk9=Aj1UtVyKa.LB Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable On Mon, 23 Apr 2012 00:46:16 -0400 Veedar Hokstadt wrote: > Thanks for your reply but setting IMSM_NO_PLATFORM seems to have no effec= t... >=20 > % export IMSM_NO_PLATFORM=3D1 > % echo $IMSM_NO_PLATFORM > 1 >=20 > % mdadm -V > mdadm - v3.2.3 - 23rd December 2011 >=20 > % mdadm -E -v /dev/loop2 > mdadm: No md superblock detected on /dev/loop2. Hmmmm.... Looks like you need IMSM_DEVNAME_AS_SERIAL=3D1 as well. IMSM like to know the 'serial number' of each device and gets confused when there isn't once ... and loop doesn't have serial numbers. I should see if I can fix that. Thanks NeilBrown >=20 > % export IMSM_NO_PLATFORM=3D"" > % echo $IMSM_NO_PLATFORM >=20 > % mdadm -E -v /dev/loop2 > mdadm: No md superblock detected on /dev/loop2. >=20 > And trying to assemble fails... > export IMSM_NO_PLATFORM=3D1 > % mdadm --assemble /dev/md0 /dev/loop1 /dev/loop2 > mdadm: Cannot assemble mbr metadata on /dev/loop1 > mdadm: /dev/loop1 has no superblock - assembly aborted >=20 > Regards, > V >=20 > On Sun, Apr 22, 2012 at 5:58 PM, NeilBrown wrote: > > On Sun, 22 Apr 2012 17:00:04 -0400 Veedar Hokstadt w= rote: > > > >> Consider a SATA drive /dev/sdb which is a member of an imsm RAID0 arra= y... > >> > >> % sum /dev/sdb > >> 25645 156290904 > >> > >> The drive was imaged to a file without error and mounted as a loopback= device... > >> > >> % sum /dev/loop2 > >> 25645 156290904 > >> > >> The checksums match as expected. But I can not examine the loopback I = get.... > >> > >> % mdadm =A0-E -v /dev/loop2 > >> mdadm: No md superblock detected on /dev/loop2. > >> > >> But I can examine the physical source drive /dev/sdb... > >> > >> % mdadm =A0-E -v /dev/sdb > >> /dev/sdb: > >> =A0 =A0 =A0 =A0 =A0 Magic : Intel Raid ISM Cfg Sig. > >> =A0 =A0 =A0 =A0 Version : 1.0.00 > >> =A0 =A0 Orig Family : e92a11d9 > >> =A0 =A0 =A0 =A0 =A0Family : e92a11d9 > >> =A0 =A0 =A0Generation : 00001608 > >> =A0 =A0 =A0 =A0 =A0 =A0UUID : 25137636:2ff64e75:10ae5444:4e8f609b > >> =A0 =A0 =A0 =A0Checksum : e1237b20 correct > >> =A0 =A0 MPB Sectors : 1 > >> =A0 =A0 =A0 =A0 =A0 Disks : 2 > >> =A0 =A0RAID Devices : 1 > >> > >> =A0 Disk01 Serial : 8068C3QVT > >> =A0 =A0 =A0 =A0 =A0 State : active > >> =A0 =A0 =A0 =A0 =A0 =A0 =A0Id : 00010000 > >> =A0 =A0 Usable Size : 312577294 (149.05 GiB 160.04 GB) > >> > >> [Volume0]: > >> =A0 =A0 =A0 =A0 =A0 =A0UUID : 72acd5fa:35c5a901:995af79b:83a29de1 > >> =A0 =A0 =A0RAID Level : 0 > >> =A0 =A0 =A0 =A0 Members : 2 > >> =A0 =A0 =A0 This Slot : 1 > >> =A0 =A0 =A0Array Size : 625154048 (298.10 GiB 320.08 GB) > >> =A0 =A0Per Dev Size : 312577283 (149.05 GiB 160.04 GB) > >> =A0 Sector Offset : 0 > >> =A0 =A0 Num Stripes : 1221004 > >> =A0 =A0 =A0Chunk Size : 128 KiB > >> =A0 =A0 =A0 =A0Reserved : 0 > >> =A0 Migrate State : idle > >> =A0 =A0 =A0 Map State : normal > >> =A0 =A0 Dirty State : clean > >> > >> =A0 Disk00 Serial : 809BC541T > >> =A0 =A0 =A0 =A0 =A0 State : active failed > >> =A0 =A0 =A0 =A0 =A0 =A0 =A0Id : 00000000 > >> =A0 =A0 Usable Size : 312577294 (149.05 GiB 160.04 GB) > >> > >> I'm trying to recover data from a failed RAID0. > >> I can successfully reassemble the RAID0 from the image files using > >> other proprietary recovery software. > >> But I would like to get it working with mdadm if at all possible. > >> Any ideas? > >> > > > > Try setting =A0IMSM_NO_PLATFORM in the environment: > > > > =A0IMSM_NO_PLATFORM=3D1 mdadm -E -v /dev/loop2 > > > > or > > > > =A0export IMSM_NO_PLATFORM=3D1 > > =A0mdadm -E -v /dev/loop2 > > > > I think this is fixed in more recent mdadm. =A0You still need IMSM_NO_P= LATFORM > > to create or assemble an array, but not just to look at it. > > > > NeilBrown > > > > > -- > 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_/WVj2zfRvk9=Aj1UtVyKa.LB Content-Type: application/pgp-signature; name=signature.asc Content-Disposition: attachment; filename=signature.asc -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.18 (GNU/Linux) iQIVAwUBT5Ti9jnsnt1WYoG5AQL1yhAAwrYXlkw2n/wJBTeYIRDbNS1j4u5DG/dd COIh8gblEM0sdbef54WIWmWlukBCm7XB86+JqVhR0mWQXgZmvc/S2Y29bBFQmJI8 mVQ/I6O1EdsULY2gAdvbA2j7MA3KTb4kMLL73XceYV3N+ZkFI+bis3L2Ha9Ef4Mc 3xxvumqMucfkudQpDTM8k0uu6ehTpkB/qG8FKDbRlmycrHwKA0mMq5sGEFSaw2zW ScREK9YYR4zN1Cc19FNQQv4IR7NLrouRuhVBcJ7WJG6JJgqCnV7xVPcFl/B7ZkKI KWMYWW9t11gAjAX3fM/e47B6pmr351cFP1nBDCj8MgmMnCnckJH8hXU3dkHIitJd T+Nx2rpg/v3c5gvwsaJhs79XZTlKksiW3DAkH8MgTL93UdK4dDuATPu/YzCJfrgu KoNNRVuk1fpl86CTYE4mcoOW/h9yh6YWUIXAge+F8u0gg7XVF3x9ie872oQdHjCb 1foR+iMAAGVDFHzkIX7cjqkre/QS5goibqpz3qux3OSdR2F8p1AI1iwi8wxwizTU VyX87BOMj4gge8Oy4ZgjauqIVsWyiQkAlZ+sQEEK7D0lv2ioCg+cddV2TQ/OZiOS FwMwXE4sbpmLk8NLyN0fDY2krrGThEr0ZmWnIBwPoUwo0t79RZp/X1MDllR397Rx 3JOzYuZ/6JQ= =jMZg -----END PGP SIGNATURE----- --Sig_/WVj2zfRvk9=Aj1UtVyKa.LB--