[PLUG] Mounting RAID partition with live CD

[John Jason Jordan]

My new desktop has two 320 GB drives. I set up three RAID 1 partitions,
two when I installed Etch amd64 from the Alternate CD and one more when
I installed Feisty, leaving 249 GB as free space in which to store
backups. Currently md0 is swap, md1 is Feisty, md3 has an aborted
version of Etch and I will just leave it there in case I want to
install a trial version of something else some day. All was well,
except I wanted to create the backup storage partition as RAID 1 also
(249 GB). I have asked and searched everywhere for a tool that can
create partitions and set up a Linux software RAID 1, but have come up
empty. Gparted can see RAID partitions, but cannot create or delete
them.

So today I decided the only way to create the new partition was with an
install CD. I used the Feisty amd64 Alternate CD. It refused to set up
the partition unless I gave it a mount point, so I did. After it
formatted the new 249 GB RAID 1 partition with ext3 I aborted the
installation. But when I rebooted I discovered that it had messed up
something on md1 -- got an intramfs prompt with the error message that
it couldn't find tty. Note that is is not a command line; Linux did not
finish booting, so all the intramfs prompt gives me is a very limited
list of commands.

I was assuming that md1 was intact and all I need to do is get into it
so I can edit the Grub menu.lst file. I booted Aaron's rescue CD and
mounted md1. However, looking at the files in /boot/grub, all are
unchanged. So the problem is not in menu.lst. In fact, thinking about
it, I now realize that the Ubuntu start splash screen started to come
up.

There is nothing that I cannot rebuild on the installation of Ubuntu on
md1, although it would take half a day of configurations to get back
where I was. I considered that doing so might be the simplest solution,
but there are two other considerations: 1) Doing so I would not learn
how to fix a messed up installation and, 2) If I reinstall, I don't
think the partition editor can create any more RAID 1 partitions than a
swap and a root partition. You must specify a mount point or it won't
create the partition. In other words, I'll still need some way to
create the third RAID 1 partition. (And I'm not sure that what I did
today actually created it.)

Any suggestions?