Well --- back from holiday :-) and everything is borken - even my ability to type it seems
My main house server (every nerd has one) that sits in my datacentre (loft) is ill.

I thought I was prepared. A pair of software mirrored RAID-1 SCSI disks shouldn't go wrong very often but they seem very troublesome.
I thought I was prepared - I thought having two copies of the data was a good thing but of course you need three, or more.
In my misaprehension I had failed to relaise that RAID provides very nicely for the completely clean failure of one disc, but what if data gets corrupted?
You have two copies they are both different what do you do?
In fact for a RAID-1 array as you read from both discs interchangable you never know that data is corrupted.

The problem
was made worse by the fact that they were boot discs as well, and I had only set up one to boot the system. Doh
was made worse by the fact that I didn't really know my way around the raid tools
was made worse by the fact that you have yet another weird layer between you and your data.

I am now seriously put off RAID solutions, and other disky things like LVM (Logical volume management - no more repartitioning nightmares) because although they may do cool things for the home user who justs wants his machine to work, a good set of backups is just a lot easier.