Our online backup is located in four data centers and we have high desity clusters in each with extra server capacity. So if a company has virtualized their infrastructure using VMware or Microsoft virtual server or hyper V we could restore their servers and run them on our hardware in the event of a disaster. We are using Dell hardware which are easy to expand. The generation 3 1950 and 2950 can take 8GB sticks of RAM up to 64GB and the newer R900's we have deployed can hold up to 256GB of RAM and 4 cpu's. With the use of our high speed SANs recovery is quick and easy.
I remember back in the day when a migration took a weekend and a lot of pain and suffering, now it's as easy as copy and paste.