[X4U] MacPro RAID setup

[Wes James]

On Thu, Apr 26, 2012 at 5:47 PM, alexandre <list at kapellos.com> wrote:
> Hi
>
> Last week I bought a MacPro 2x2.4GHz (mid 2010), with a 2TB hard drive. At the same time, I bought a 120GB SSD onto which I loaded OS 10.7.3 and all my applications. Over the weekend I'll be buying 4 3TB drives that I'll setup as a RAID. Since I'm not very familiar with RAIDs and despite some intense googling, I have a few questions.
>
> I understand the difference between RAID 1+0 and 0+1, but which is safer? I've read that one is better than the other but I haven't really understood why.

Based on the second and third links below, I'd say RAID 1+0 (also
called RAID 10) is safer.  Safer in that your chances for total
failure are less.

> What are the advantages of a nested RAID over, say, 2 independant striped RAIDs where one is a Time Machine backup of the other?
>
> I'm not so much interested in speed as I am in keeping my data safe. Should I go the nested RAID route (0+1 or 1+0), I will be backing up to 1 or 2 external FW 800 drives.
>
> FWIW, I work a lot with photographs (RAW files).
>
> Any tips or additional information is appreciated!
>
> Regards, Alexandre

Here are some things to look at if you haven't already:

General Info
http://en.wikipedia.org/wiki/RAID

Why is RAID 1+0 better than RAID 0+1?
http://aput.net/~jheiss/raid10/

RAID 1+0 is the Cadillac of RAID
http://www.zdnet.com/blog/storage/raid-1-0-is-the-cadillac-of-raid/131

I'm glad you also mentioned that your are backing up, as RAID is not
"backup", but a method for maintainingg up-time.  It provides an
increased hope factor that you will have time to replace the failed
disk and rebuild the RAID before any more disks fail and you have to
take the time to restore all from backup, which can equate to a much
longer down-time.

-wes