A few years ago I bought a Dell R610 to add to my fleet of servers. It did alright but I had always dreamed of having better storage. I found a Dell Direct Attached Storage array on eBay for cheap. It had some mismatched drives but they were all the same size and it seemed to run. I bought the external RAID card for the R610 and hooked it up. I loaded VMWare ESXi 6.0 on the server and it immediately saw the storage. I had some questions about RAID on the array but settled on a RAID 5 across all the disks. Between the 512 MB cache on the card and spanning all of the 10k RPM SAS disks it is fast. It is much more difficult to bottleneck the disks. I learned a couple good lessons from this. That many disks running in your basement will function as a space heater. More importantly I learned the importance of a good RAID controller. Having that cache really helps prevent the disks from getting bogged down when multiple VMs try to read or write to the disks.