Bootable USB RAID Partition Help Please!

[jshafer817]

Hey guys I am new to the forum which means I am at my wits end! USually I just lurk and can find the info I need but this time I am at a loss.

Here is the problem. I am using GRML which is a debian livecd, sorta. I had it create a hard drive installation with raid being my boot partition, except I am doing this with a usb external drive. I am using SWRAID='mbr-only' grml2hd /dev/md0 -mbr /dev/md0

I create md0 with two usb drives before running grml2hd. They are like /dev/sdb1 and /dev/sdc1. And actually I created it by their diskid so I used mdadm --create --verbose /dev/md0 --level=raid1 --raid-devices=2 /dev/disk/by-id/blahblahblah /dev/disk/by-id/seconddriveblahblah
and it creates md0 successfully, installs grml2hd and lilo sucessfully on the MBR of the two drives. It also seems to want to use LILO for a reason I think having to do with a raid-extra-devices option with lilo. I read grub has problems booting raid1 bootable partitions, or something.


But when I go to boot initramfs cannot find my md0. I went looking in /dev and when I insert the usb drives they are not being assigned in /dev, so I cant use mdadm to at least start md0, and continue booting. My internal drive is being assigned as /dev/sda so thats good, but I dont want to use my internal drive at all, so oh well. It is nice to know that it can be seen.

IS this a kernel problem? I checked /etc/initramfs/modules and it looks good, recreated the init file and still the kernel cannot find my usb devices.

But if I boot into the grml live cd my usb devices are found in /dev at boottime, but not when I boot from usb, and then I sit at initramfs menu.

Furthermore (maybe a dumb question). In busybux, with initramfs, if I could somehow get my usb devices to be seen as /dev/sdb1 and /dev/sdc1 and then could use mdadm to assemble md0, how could I continue booting?

Doesnt seem to matter at this point, because my usb partitions are not being assigned as /dev/sdb1. I cant tell what they are being assigned as.

I do know if I install grub, tell grub to use /dev/disk/by-id/blahblah instead of /dev/md0 grub has no problem booting with my usb disks, but raid is not working with this setup.

And if I plugin the usb device while in busybox\initramfs menu I see them being assigned as scsi sdc or sdc, but when I look in /dev I dont see them.

Please I have tried for 4 days straight. I should have asked sooner. I have learned quite a bit. My partitions have the "FD" autodetect in the id and they are bootable.

I dont know why its not working.

I want a bootable usb device that can do raid1 with its bootable partition, and I want hardware detecition. So its like a portable server. I want it to also be able to boot if 1 of the devices in the array is missing. Like imagine 3 drives in an array on a server. /dev/md0 is the only partition on the system and includes /boot. If the server dies for some reason I want the ability to take the usb external drive, and boot it on another pc, and boot it as md0 not as the /dev/disk/by-id....

I tried this with the ubntu live cd and it I dont know if the unionfs can merge with raid. (maybe). But ubuntu has a pertinence issue. I gave up on setting this up as a livecd\livehd and decided to do this as a normal linux install. But I am thinking of trying to use the unionfs with grml to acheive hardware detection, boot from usb, and have the usb bootable partition be part of a raid array.


Please help.

PS LILO loads incredibly slow with dots while grub loads really fast, neither can boot my md0. I thinkk I can fix lilo with lilo -c -v or putting a compact option in lilo.conf, but I will worry about that once it sees my array at boottime and can start INIT.

[jshafer817]

Let me try to clarify one more time..

IF I boot off GRMLLive CD, remove usb drives, insert usb drives, it will assign them as /dev/sdb1 and /dev/sdc1 and I can manually start md0 using mdadm and then continue to the grml2hd install.

If I boot off the usb drives... I end up in initramfs and no matter what I do (eject and reinsert) the usb drives... I dont see their partitions assigned in /dev so I can use mdadm to manually start the array to finish booting.

Perhaps booting off a usb bootable raid partition is not yet supported with Linux Kernel?

[jshafer817]

Maybe if I have /dev/sdb1 being /boot and not raid and /dev/sdb2 being root and md0 it would work? Instead of /dev/sdb1 being / and /boot with raid?