LaCie 3TB Big Disk (or 2Big) vs. RAID Disk Array

If you are going to build a RAID array from scratch, why use 0? If one disk fails, you lose everything. I would use RAID 5. It takes up more disks, but has built in redundancy. After all, RAID stands for Redundant Array of Independent Disks... what's a RAID without redundancy?

From Wikipedia:
RAID 5 (striped disks with parity) combines three or more disks in a way that protects data against loss of any one disk; the storage capacity of the array is reduced by one disk.

RAID also stands for:

Rapid Array of Inexpensive Disks
Rapid Array of Indpendent Disks
Redundant Array of Inexpensive Disks
...

The acronym just means "the use of smaller drives to make a big one and/or one with more security."

In using software RAID for these devices, I'd recommend using RAID 0 (striped) for speed, but do keep in mind that if one drive fails the whole array will be lost, so dont store important information on these disks...keep a backup somewhere, and use the disks just for rendering and all that. Then back up the results somewhere safe(er) when you have time.

Yes, but it is more efficient to use a RAID 5 with built in redundancy than 2 mirrored RAID0 arrays for backup. You save disk space and $$$ in the long run.

That's true, however, OS X does not support RAID 5 in software, so he'll have to get a separate enclosure that supports that RAID level. The best way to get redundancy and size in OS X is to concatenate two mirrored disks...losing half the available storage space to redundancy, but getting a larger disk than each independent one.