[CentOS] "conventional cluster management software"

I saw this in the openfiler thread, and realised it is another major
hole in my knowledge

What do you all use for clustering, and does it run out-of-the-box with CentOS?

My main areas of interest are :
- DB clustering (PostgreSQL) - yeah, we're looking at commercial stuff
and skytools
- web server clustering - Apache on CentOS
- storage clustering

thanks,
-Alan

-- 
“Don't eat anything you've ever seen advertised on TV”
         - Michael Pollan, author of "In Defense of Food"