We have two production Tiger servers, and I decided I wanted to get RAID1 set up on the Server HD itself.  Apple tells you this isn’t possible without reformatting/reinstalling.  AFP548 tells you otherwise:  http://www.afp548.com/article.php?story=20040827122302975

However, I spent several hours trying to get this operational with no success.  If you look in the comments of that article, I’m not the only one.  I was probably leaving out an important step somewhere, but after a few tries of reformatting, etc, you get a little brain fuzz.  I’m sure being there at 2am wasn’t helping either.  :)

I decided against doing this for now.  Instead I opted for a nightly incremental clone using Carbon Copy Cloner to the second HD.  In hindsight, this is probably going to serve me better.  Let’s say an update goes awry and renders something unusable.  I still have yesterday’s clone to boot to!  Hardly anything changes on the server HD itself, since these servers are just file servers, so that works out well.  I can see this not being a good setup for some depending on what kind of server you’re running and where the important data is actually stored.  In my case, we have 3 Apple RAIDs at ~17TB total (older, but still running), and just bought an Active XRAID 16TB to compliment that 17TB we already had.  All configured in at least RAID5, with the Active XRAID set up with 2 dual parity RAID6 slices.  Plenty of protection there.  And of course, RAID is NOT backup!!

When our next server comes in, I’ll probably set up a RAID1 mirror with a CCC clone to a single 3rd drive, or maybe use the 3rd drive as a hot spare.  I’m liking the idea of having an operational 1 day old backup, so the first is more appealing.

On a side note, I’m interested to see what RAID storage offerings Apple will be offering now that Snow Leopard Server will do ZFS*.

*Apparently, Apple seems to have removed ZFS from it’s Snow Leopard page.  Say it isn’t so!!