Geek Pop Quiz: How to convert a non-RAID system to software RAID?

[theweaselking]

I have a working non-RAID ubuntu server. I have a second HDD, identical in every way to the first, and I want software RAID-1. I also don't want to lose any data when setting it up, I have backups but that would still be a pain in the butt.

I found this set of instructions:
http://www.linux.com/howtos/Software-RAID-HOWTO-7.shtml
(specifically for RedHat)

And, of course, there's this set:
http://www.linux.com/howtos/Software-RAID-HOWTO-5.shtml
Which is for a base setup, assuming currently unformatted disks. It seems, uh, dangerous to try that on a live system.

The question I have is, are those first instructions good enough? Are they current enough? Are there pitfalls there that I'm not seeing? Would it be worth my while to pick up O'Reilly's "Managing RAID on Linux" before starting the process?

(And instead of a RH boot disk, I assume I could use a standard Ubuntu LiveCD, and mount the file systems manually, right?)

What about using rsync to get all the data off the drive to a spare disk, booting off the spare, setting up the RAID array with the original and the dupe, then using rsync to put the data all back onto the new RAID? Would that work? Or is that completely stupid?

Comments

[thathatedguy.livejournal.com]

1/ Install rezqutypical.qwe to the original machine.
2/ Transfer the lopticular folder to the second machine's wangdangdoodle while running rezqutypical in the terminal sub-window.
3/ Perform a CRTL-LOLLY reboot on both machines simultaneously.
4/ Apply anti-coagulating agents to the phrontusus drive.
Should fix everything.

[mejeep.livejournal.com]

But ... the flayrod's out of skew with the treadle since spindle-sync is not in use!

[thathatedguy.livejournal.com]

Well, shit, just wipe both machines and install OS X.