> The reason for my question is MySQL's "cluster" support.
> My reading of it is that their "clusters" have nothing to
> do with what used to be called clusters - groups of
> machines that share disk but not memory. The MySQL site
> claims that their clusters give "high availability" aka
> "5 nines". Looking more closely, "5 nines" means 99.999%
> up time. Sounds good. 0.001% of a week is 10 minutes.
>

hate to be a pedant but it's more like 6 secs by my calculator

Pete.