We are on the edge of some dramatic changes in computing infrastructure. New packaging methods, ultra-dense SSDs and high core counts will change what a cluster looks like. Can you imagine a 1U box having 60 cores and a raw SSD capacity of 1 petabyte? What about drives using 25GbE interfaces (with RDMA and NVMe over Fabrics), accessed by any server in the cluster?
Consider Intel’s new “ruler” drive, the P4500 (shown below with a concept server). It’s easy to see 32 to 40 TB of capacity per drive, which means that the 32 drives in their
concept storage appliance give a petabyte of raw capacity (and over 5PB compressed). It’s a relatively easy step to see those two controllers replaced by ARM-based data movers which reduce system overhead dramatically and boost performance nearer to available drive performance, but the likely next step is to replace the ARM units with merchant class GbE switches and talk directly to the drives.
I can imagine a few of these units at the top of each rack with a bunch of 25/50 GbE links to physically compact, but powerful, servers (2 or 4 per rack U) which use NVDIMM as close-in persistent memory.
The clear benefit is that admins can react to the changing needs of the cluster for performance and bulk storage independently of the compute horsepower deployed. This is very important as storage moves from low-capacity structured to huge capacity big-data unstructured.