Actually, there were 3 of them. 1 running Apache and Perl FastCGI, one running MySQL, and a third which mostly ran backups, but could be used as failover for either the web server or database if required. I used to fly from Sydney to San Francisco 3 or 4 times a year with half a dozen hard drives in my carryon, because that was the most reliable way to do major upgrades - we had three identical boxes in the office in Sydney, and would install/configure/test major software and dependancy upgrades in house, then go to the data centre and swap in the new drives one machine at a time with zero downtime - usually. I was rarely the only one in my datacenter aisle with a screwdriver and a PAIX guy looking over my shoulder, but most other people were swapping out whole rack mount servers, not opening them up to replace or upgrade components.
