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 <hbarta@xxxxxxxxx> 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/...) > > 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<n> > --uuid <UUID>' individually for the RAID devices I wanted to start. > > 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. > > 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. > > Is there something I overlooked in getting it started in this > particular situation? > > 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. > > many thanks, > hank > > -- > '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@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html
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