[Velocity211]

I'm planning to get a 24" iMac and was wondering if I can have a RAID 1 setup with a 500GB internal HD and an external FW800 500GB drive. Is this even possible? If it is, will it slow down my computer too much?

[MacosNerd]

I don't think its possible to construct a raid array across internal/external drives. What happens if disconnected the external drive? I'm not even sure the disk utility software will let you select an internal and an external volume when creating the RAID array.

[mduell]

Should work, but should be slowish.

I'd just wait for Leopard and use Time Machine (since it's an actual backup, which RAID is not) unless you have some genuine high-availability need

Originally Posted by MacosNerd 

I don't think its possible to construct a raid array across internal/external drives. What happens if disconnected the external drive?

You should be able to have an array off any two (or more) drives, regardless of bus.
Disconnecting the external is the same as breaking the array any other way (dead disk, etc). You'll have to rebuild the array when you reconnect it.

[OreoCookie]

It's possible, sort of, but definitely not advisable. It would slow down your computer somewhat as the FireWire drive is slower than your internal drive. Furthermore, it wouldn't give you much of a benefit anyway. If you look for data security, you should refine your backup strategy (if you have one).

[Velocity211]

Ok thanks for the input, I was gonna wait until leopard came out to get an iMac anyway, I guess Time Machine is a good way to backup my data.