I'll try to answer all the questions here in one shot. Wish me luck! :)

>mdadm --stop /dev/125
>mdadm --assemble /dev/md0 /dev/sda1 /dev/sdb1

I tried that but still didn't get back to bootable.  It's hard to see
what went on when the system halts (my thanks to whoever changed the
video mode to get more on the screen during booting in SL6!), so I
won't swear that it didn't go back to /dev/md0 and something else was
awry.

In fact, I just tried this now on an old machine with the same config
and manually assembling the RAID sets with the correct devices
corrected the problem. I'm not sure what went wrong with this
yesterday. I may try it again a time or two just to make sure I'm
doing this right.

Of course, you'll need to know what the correct devices are, but since
you've got your system root (somewhere), you can mount it and look at
your fstab or look at the filesystem labels, or even the contents to
figure out which is which and where it needs to go.

>Are your raid partition of the type 0xfd (Linux RAID autodetect) or 0x83 (Linux)?

0xfd, RAID autodetect.

>BTW. The LiveCD already boots with "rd_NO_MD" and "rd_NO_DM" options which >should disable MD and DM RAID detection.

I didn't change any boot options, other than removing the rhgb and
quiet options so I could see what was going on. Call it a quirk of
mine, but I dislike systems that just sit there with maybe a little
animated icon; I keep wondering if it's making progress or not.
Anyway, those options are present on the LiveCD.

>Bluejay: Which LiveCD version are you using? The released version of 2011-03-07 or >some testing versions prior to 2011-03-07?

It's the 2011-03-07 version of the regular CD.

>I was pretty sure that rd_NO_MD and rd_NO_DM are the right options to use
>(according to man dracut). But maybe I'm wrong and "rd.md=0" and "rd.dm=0" are
>the right options to disable RAID detection. Could you please test this?

I tried adding rd.md=0 and rd.dm=0 and it still assembled the RAID
sets (with the wrong device numbers).

>Bluejay, do you see /etc/mdadm.conf, if you boot your system with the LiveCD?

Nope, no /etc/mdadm.conf on the CD.

Thanks for the suggestions and interest in this.

                 - Bluejay Adametz, CFII, A&P, AA-5B N45210

No matter where you go, there you are. Which is good, because
then you can always get to where you're going to be.

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