Our customers often ask what storage technologies they should be using. The answer, invariably, is complex. There’s no right or wrong answer. But, choices made now will have an impact on how well the system will perform in the future so, careful, intelligent planning is essential.
If you need a large amount of performance and less capacity, the cheapest way to achieve that is with Flash / Solid State Drives [SSDs] – the cost per Input/Output Operations Per Second (IOPS) is much lower than disk or tape. But, it is of course, much more expensive per TeraByte of capacity.
Filling your rack with flash for capacity would be very expensive and, similarly, filling racks instead with Hard Disk Drives [HDDs] to achieve performance wouldn’t necessarily be the most cost-effective route either (although it can be, and is, done – when it matches a customer’s mix of performance and capacity).
Generally, we suggest a mix of both flash (for performance) and HDDs (for the capacity). In HPC storage systems, for example, we often use flash for metadata, very small or recently used files, yet still use HDDs for capacity. Most of our Storage Area Network (SAN) storage array partners have technologies that allow SSDs and HDDs to be added into the same disk pool automatically.
In the near future, I can also see our customers using SSD/Flash cache devices in front of large HDDs to get the best of both worlds. And, with SSDs getting larger and cheaper it does beg the question of whether or not we could get rid of the disk tier altogether and operate a flash + tape model?
There are, today, some very specific applications where using flash and tape is by far the most cost-effective storage setup. We’re certainly not at the tipping point where this kind of solution would be right for everyone but the number of customers looking into these solutions in both enterprise and research organisations is growing.
Many organisations have performance and capacity use cases for all of the technologies I’ve described above, the challenge is bringing all of those technologies together in a unified way so you don’t end up with inefficiency through poor utilisation.
I think it’s safe to say there is no one-size-fits-all answer on what the perfect storage media mix would look like, but as we see prices of SSDs come down, capacities of HDDs go up and the sheer cost effectiveness of tape, the way we build our storage solutions will continue to evolve.