Replacing a failed HD in a raidframe array

[Jason Murray]

I previously had a bit of trouble with my raid array. That is now cleared 
up and I need to replace one HD of the mirrored set. Never having done 
this I thought I'd check here to see if there was any advice on HD selection.

Natrually the replacement HD will have to be at least the same size as the 
original. But are there any restrictions on HD geometry?

It naively makes sense to me to try match things as closely as possible. 
Or am I way off base here?

Thanks in advance.