[LAU] HOWTO, AVLinux --> LVM?

[Jonathan E. Brickman]

OK, I am officially intrigued :-)  My focus is live; I do recording 
sometimes on laptops and then immediately copy it elsewhere, but my 
primary is a desktop box set up for transportability with two laptop 
hard drives, running ZynAddSubFX (Yoshimi from now on I think) and 
Qsynth as MIDI module with my keyboard.  I have a third desktop hard 
drive installed also, not being used, as an aid to moving it all to 
RAID-1 which has seemed likely.  But now I understand positively that 
LVM drive mirroring is an option.  A few questions:

1.  What are the advantages of LVM drive mirroring over RAID-1?  I 
understand that one advantage is mdadm update issues; I have had a 
machine hosed this way too.  Are there other advantages?

2.  If I set up LVM drive mirroring, can I boot off either drive?

3.  How do I set up LVM drive mirroring?

4.  If I set up LVM drive mirroring and take a drive out, can I put that 
drive in another machine and expect it to boot?

J.E.B.