As The Mamas And The Papas Once Harmonized . .

"Monday Monday, so good to me,

Monday Monday, it was all I hoped it would be

Oh Monday morning, Monday morning couldn't guarantee

That Monday evening you would still be here with me."

It's early Saturday afternoon. I'm thinking about Monday, a big day. It's the next step in our transition, as the Mac Pro and the Apple Cinema Display are scheduled to be delivered. I can honestly say that I haven't been this excited to be receiving a new computer in over a decade. Here at home, the 24GB of new OWC memory, the eSATA controller card and the two Seagate Barracuda XT drives await their new aluminum quarters.

Over the weekend, I had some time to figure out how to set-up the internal RAID "set" in my Mac Pro. My Mac Pro ships with a single 1TB internal HDD and I was planning on creating a RAID array as a measure of safekeeping.  For those of you who do not know the acronym, RAID stands for "Redundant Array of Inexpensive / Independent Disks". Specifically, I am planning to implement a RAID 1 Mirror, where data will be written to both drives simultaneously,creating a favorable redundancy. Simply put, if either drive fails, the other will continue to function as a single drive until the failed drive is replaced. I have heard decent comments about an aftermarket software product called SoftRAID, but thought that I'd investigate Mac OS X Lion's "built-in" (software) RAID creator, which can be accessed by using Disk Utility.

Before I move on, I should emphasize that RAID 1 is NOT a backup. It's commonly used as a strategy for data redundancy, but by itself, is not effective as a backup. One major reason is that any data written to the RAID is immediately copied to the mirrored set. If you then go and erase a file, it essentially disappears from the mirrored set of disks. Therefore, you cannot access an older version of the file, such as version created a day ago. Understand this concept so that you'll have a "real" backup strategy in place!

The Steps for a two-disc RAID 1 Mirror Set in OS X Lion (mostly plagiarized from the Apple Support website):

1. In Disk Utility, select one of the disks in the list that you want to use in the set and click the "RAID" tab.
2. Type a name for the RAID set (RAID Set Name) and choose a format from the Format drop-down menu. The default, "Mac OS Extended (Journaled)" should suffice.
3. Choose a RAID Type, in this case "Mirrored RAID Set"
4. From your list of disks in the left-most window, drag the first disk that you want to use in the RAID to the set list window on the right.
5. Click on the disk that you just added to the set. For "Disk Type", select "RAID Slice".
6. Click the "Options" button to specify an optimal block size for the data stored on the set. This block size is dependent on the type of data that you will be storing on the mirrored set. Unless you are storing very large files, for general use, 32K should suffice. Also select "RAID Mirror AutoRebuild". Click OK when you are finished.
7. Drag the second disk to be utilized into the RAID Set window and repeat steps 5 and 6.
8. Finally, click the "Create" button.

After you create the RAID set, the operating system manages storing files on the disks in the set for you.

Please note that after you click the Create button, a warning will remind you that all data on the drives that make up the new RAID array will be erased.

Disk utility will then create the RAID 1 mirror set, renaming the individual volumes that make-up the RAID set to RAID Slice. It will then create the actual RAID 1 mirror set which will ultimately mount on your Mac's desktop as a normal hard drive.

At this point, I haven't decided if I want to retain the single 1TB HDD that ships with my Mac Pro along. If I do, I would then have a total of three drives spanning the Mac Pro's drive bays.  Contrarily, I could ditch the 1TB drive and employ only the pair of 2TB drives in the RAID set.  A third option is to keep the 1TB drive and utilize it as a Windows partition, so that I could load and refer to Sofdent's historical data.  I like to keep things simple, so I'm leaning towards just the two drives.  

To be continued . . .