Server aggregation using VM technology

If you're a small organisation with a few servers supporting the usual function such as mail, file & print, database, etc., you've probably got dedicated servers for each function. But as the servers reach the end of their warranties, before rushing out and replacing them, give some thought to virtualisation as an option.

Previously the domain of large IT enterprises, with the advent of Windows Server 2008 and Hyper-V, together with the free version of VMWare, virtualisation is now reachable for small organisations also. A company with up to 100 staff with a reasonably predictable workload, can be well served with two enterprise servers (single or possible quad core CPU's) and ample RAM (128MB) running Hyper-V. A rule of thumb is each core on a CPU can support one VM so with sufficient RAM to avoid paging, even two single socket quad core servers can support up to 8 VM's.

Having made the decision to go virtual, one shouldn't stop there. With a number of real servers there is always the issue of managing attached storage. Storage on the Exchange server say, cannot be used for the file and print server and vice versa. That leads to a waste of storage that many small IT shops face.

What to do? Storage virtualisation or lower cost SAN options are now also reachable for the small enterprise. Deploy an iSCSI SAN on the network and provision file and print, mail (Exchange) and SQL on that SAN (assuming you are in a gigabit backbone). Then only attach sufficient storage to the servers (say 75GB or so) for booting and local paging and now you have a very efficient data centre operation with room to grow, both from a CPU point of view and storage point of view.