I'm just looking for some clarification on what happens in the event of a controller failure on a SAN. Our outsourced IT recently had an issue with a HP SAN where the controller failed and as there was no secondary controller, they had to order a part and then restore the unit. The Outsource company is recommending we buy a second controller as we have the same model as one that they had issues with. All our VM's reside on this controller, there are weekly full VM backups to another physical machine.
Just wondering if the data is always safe in this event as they are saying the data is safe. Is this correct? How is the info stored on the disks? I'm not a storage specialist so would like advice from those who are.