[LAU] HOWTO, AVLinux --> LVM?

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.