I was the offender..... :0 Sorry about that.

I think the thing that I didn't understand was what the config was actually doing in an operational sense. Andy sort of touched on it here.

The article had three drives in the RAID1 array. Since RAID1 is mirroring, I've never seen 3 drives in a mirrored array. So I was wondering if one drive is actually mirrored to the other 2 in the array.

Then on top of that, the RAID1 array had a spare drive..... So three active, 1 spare. I wasn't sure what that meant it was doing.

So it sounds like this...someone correct me if I am wrong:

- All writes to the boot partition are mirrored to two other drives.
- If any one of the three drives fails, the fourth will automatically join the array so that the first partition is still mirrored to two others.
- If the first drive fails, then the system would boot off drive two which would then be mirrored to drive three and four.

As an aside, the main thing that I didn't like about the article was that it presumed with just 4 drives that you want a hot spare. Well, if I wanted half my total drive capacity, I'd just use RAID1 in the first place. I'm using RAID5 to get more storage space and have it be resilient. I have a spare sitting on my shelf and am not too lazy to plug it in if I need it :-).

Which brings me to another question. Anyone know of any drive monitoring software that can detect drive failures and send an email or an alert of some sort. For my needs, that is sufficient...I don't need a hot spare if I can get notification when there is a problem.