This week the Datacenter group got our new SAN. This will be our biggest project of the year and we’re all very excited about it.
A SAN (Storage Area Network) can be thought of as a gigantic external hard drive, but rather than holding files and folders with our spreadsheets and documents, it holds the software images of the servers that everyone uses all over campus. These software images are called Virtual Machines (we call them VM’s for short), and we use special software to get many of them to run on a single computer at a time. This way just one Dell server, connected to a SAN, can run the software of many servers all at once.
We also use software that enables these servers to failover from one physical computer to another, if they’re both attached to the same SAN. This way if one of the physical computers has a problem, like a part gone bad, rather than the whole server shutting down, the workload (VMs) of that server are transferred to another server, which takes over and continues the work of itself and the failed server. This is great when you’re trying to get some work done and the server has a problem – you never notice, and we datacenter folks take care of it in the background without faculty, staff and students having to worry.
Our new SAN makes this even better. We’ve been using SANs for many years, as have most universities and businesses. But this one is larger, faster and more redundant, and therefore can hold more information and distribute that information faster than ever before. While our older SANs consisted of large groups of identical hard drives, this one, an EMC VNX 5300, has differing sizes and speeds of drives and can detect when a resource is being used more than others and offer that resource faster access. And while our fastest existing SAN could perform 7400 operations per second (IOPS) and stored up to 35,100GB of data, the new one can perform 56,920 IOPS and stores up to 88,800GB of data. So it’s a lot faster and can store more than twice as much.