If you’ve never heard of a SAN (Storage Area Network) before, it’s probably because it’s been available only to enterprises with large budgets.
SANs are a way of providing disk based storage via network connections (usually fibre) rather than internally to the machine. One of the advantages of this is that several machines can access the same “virtual” disk at the same time. You may wonder why this would be useful as each machine would have a fast local disk anyway?
Well, when you share a SAN volume, you can enable clustering which means that loads can be shared between machines, and this also provides redundancy should one of them die.
The latest use of SANs however is with the growing adoption of virtualization. Products such as VMWare and Microsoft’s Hyper V allow many virtual machines (VMs) to run on one physical machine. When connected to a SAN, it’s easy to move a VM from one physical server to another – and live with no disruption!
So, this brings me back to the cost of SANs. Typically in the past – a SAN implementation would’ve cost many tens of thousands of dollars and was complex to set up. This is still the case for large high performance SANs with fibre interconnect and multipath redundancy.
However Starwind have recently released a free version of their iSCSI for Windows. This allows you to turn any 2TB windows server into an IP based SAN for free! By using gigabit ethernet instead of fibre, it’s possible to create a Hyper V cluster using 3 machines (one being the SAN server) relatively cheaply.
Congratulations to Starwind on releasing such a product for free! I can see this bringing live migration and redundant VMs to smaller businesses that previously couldn’t afford it.
I for one will be playing around with this further in our lab….