Mirrored RAID help? Please!

Hi,

I have a few questions about Mirrored RAID. Apple's Tech support will not answer any questions without a $250 fee, because they deem it to be a "Pro" question.

Anyway, here I go.

1. I have two hard drives, both partitioned ("A" One internal SATA 100GB, and "B" one external firewire 160GB). I want to install Tiger on one of the partitions and have it mirrored. When I setup the RAID and try installing the OS on the new mirrored array, it says that the computer cannot startup off that disk. Am I doing something wrong or is this really the case? I can't believe that I can't mirror a startup disk for backup?

2. Also, can I not setup a mirrored RAID with both partitions. Both drive "A" and "B" have two partitions named say "Video" and "Audio." I create a mirrored RAID with partitions "Video" from both drives. If I then try and create a Mirrored RAID with partition "Audio" from both drives it will not let me. Can you only mirror one partition per drive or am I again doing something wrong?

3. Is there any way to preserve info on the drives when creating a new RAID array? I don't think so, but maybe?

4. Should I be setting these up the Mirror RAID with the partitions being "RAID Slices" or "Spares." I have no idea what that means.

5. Should I just leave the mirrored array block size at a default of 32K? For Video work is it worth bumping it up to 128k or 256k?

6. Lastly, when I create a mirrored RAID, the icon showing for the "new drive"
is for an firewire drive. Does this mean that when i read the data, that it is coming from the external drive and not the internal one. Can I set which one the computer reads off of? Does it read off both? I have no idea.


Thanks,

Florio