From mboxrd@z Thu Jan 1 00:00:00 1970 From: NeilBrown Subject: Re: raid startup on a live CD? Date: Tue, 15 Nov 2011 16:03:58 +1100 Message-ID: <20111115160358.5653769c@notabene.brown> References: Mime-Version: 1.0 Content-Type: multipart/signed; micalg=PGP-SHA1; boundary="Sig_/LMvn2aY_Y1ATWCv.OQDQOMN"; protocol="application/pgp-signature" Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: Hank Barta Cc: Linux-RAID List-Id: linux-raid.ids --Sig_/LMvn2aY_Y1ATWCv.OQDQOMN Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable Could you try again, but add --verbose to --incremental --scan, report the output, and any message that appear in 'dmesg'. thanks, NeilBrown On Mon, 14 Nov 2011 22:56:40 -0600 Hank Barta wrote: > Hi folks, > On occasion I boot a live CD and need to have the md RAID devices > running. Ordinarily (with Ubuntu live CDs) I find that I need to > install the mdadm package after booting the live CD. At that point my > recollection is that the RAID devices get started by the scripts that > perform the installation (and probably run the startup scripts that > are in /etc/init.d/...) >=20 > Earlier today I did this with a distro that is derived from Debian and > under development. I was happy to see that 'mdadm' was already > installed. (I had asked for this in fact.) But then I started > encountering difficulties. The /proc/mdstat file existed but listed no > RAID personalities and none of my devices were started. I tried 'mdadm > --assemble -scan' which reported no errors but did not improve the > situation. I manually loaded the raid0 and raid1 modules (which caused > the personalities to be listed in /prod/mdstat) and pulled in other > raid related kernel modules. However 'mdadm --assemble -scan' still > did not start my devices. I thrashed around a bit before finding a > command that probed drives and listed the md devices and their UUIDs. > I was then able to start them using 'mdadm --assemble /dev/md > --uuid ' individually for the RAID devices I wanted to start. >=20 > I'd like to report back to the person working on this distro the > difficulties I had with the RAID and beyond that, I'd like to provide > the information that they need to set up RAID so it just works (like > on a normal boot) if possible and desirable. >=20 > First... Are there reasons that other live CDs I've used have not set > up RAID? Live CDs by their nature are somewhat lightweight so if > adding mdadm uses significant resources perhaps it is best left as a > manual operation. >=20 > Is there something I overlooked in getting it started in this > particular situation? >=20 > Where should I be looking for documentation that would help > configuring RAID on a Live CD? I did some searching and the most > promising thing I found was > https://raid.wiki.kernel.org/articles/r/a/i/RAID_Boot_bac9.html which > directs me to a text file in the kernel source tree. > (http://lxr.linux.no/#linux+v3.1.1/Documentation/filesystems/ramfs-rootfs= -initramfs.txt) > And that points to other documentation. I'd appreciate pointers to > documentation that is particularly relevant to md RAID form a live CD. >=20 > many thanks, > hank >=20 > -- > '03 BMW F650CS - hers > '98 Dakar K12RS - "BABY K" grew up. > '93 R100R w/ Velorex 700 (MBD starts...) > '95 Miata - "OUR LC" > polish visor: apply squashed bugs, rinse, repeat > Beautiful Sunny Winfield, Illinois > -- > 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_/LMvn2aY_Y1ATWCv.OQDQOMN Content-Type: application/pgp-signature; name=signature.asc Content-Disposition: attachment; filename=signature.asc -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.18 (GNU/Linux) iQIVAwUBTsHyvjnsnt1WYoG5AQI9AQ/8CEa+6o+wViK6AfFOPe98DeVf8H6578Dn HEr+pJ5JchjPxbaWbO9BRuqMOF3bix4MZXXQ4Mhd95E9nunNzTQRm6n40LlCRLJG av+v92CxTFDMnxWYv0Hft8P+2R8HrFE31TtGVDDov57axxcN5zMVqqKItU0TioNz 9f+MB44Fd48p6RCmQ9bnVSyZ5CtkftRYGwKkq7S4MF9omWhLzKYjlEkOSu7eLALh ex794wJ3Re23quRN9LDijouGGtec/scRLJhjhEeSLfHeUvi4XBWJJLmrd0FH6Cwz EVDYTS7qTWDItxKsKJUbxB4yi6h5vSfj8ZU+/pMKMVJeRixYPL//cTo1i2sOio1J QrC4WY63P8y7VecM+fAobk14tV4gMJRMJBe9IRHE5HWiVDzOw3td2A5g2pM4Zt0R u8owpvE9YB+0Bz9dcwmLP5iTWRJH7rsKDcww4hdRR9dxgamk/m+mgULIuYUYqHfd Amptm/gaRSM4E9JxJBrt/6G5SXvWsRIO83kovnVmPM+WPgzQ+GFB5hLeyEE7hh8J obTI1W+XdkNlkra8VyXOE2ho6oUdGWRMrNex782wVxO4H7rKQIyMFjwjY6AOJHeJ hFcESbf8/cCOmMEgjycTnBSTF++Gl3nmObcxrgrdZvoxhb2daBRWWpdE5DQrgIuE hLgreCZXx/Y= =+V/6 -----END PGP SIGNATURE----- --Sig_/LMvn2aY_Y1ATWCv.OQDQOMN--