Rumors of Disk’s Death Have Been Greatly Exaggerated

We talked recently about the addition of new layers of performance in the storage stack and how users and storage architects are trying to make most effective use of those. These tiers include HDD, SSDs, NVMe and storage class memory with the challenging being how to decide what data goes where and by what mechanisms.

The simplest part of this emerging stack is at the base with hard drives, which do not get the attention of the most modern elements but are still getting their market share—and growing, according to Chris Bergey, GM of Data Center Devices at Western Digital.

He tells The Next Platform that indeed there is excellent growth in SSDs, which are expected to continue at 44% CAGR over the next five years on top of a reasonable base. But that does not necessarily mean this is happening at the vast expense of disk.

“Over the same time period, we believe we will have over 34% CAGR of capacity HDDs for datacenters, which is building off a much bigger base,” Bergey says. “Not only will HDDs stick around, they are going to grow because the amount of data and emerging workloads will require this.”

He explains that even in traditional enterprise areas (ERP for instance) where SSD growth has been strong disk will continue to have a place because the breadth of enterprise applications is rapidly expanding. Just as there will always be ERP and other standard applications, the capabilities fed by increasingly advanced business intelligence and machine learning will require a cost-effective, high-capacity tier to go back and do more advanced analytics.

In other words, what HDD might lose in share to SSD could be made up as more applications require a less expensive tier since cost drives so much of what happens in datacenter storage.

In terms of emerging workloads that promise continued growth for HDDs, Western Digital is looking right where one might expect in 2019. IoT and AI, which they think will jumpstart the need for high capacity storage at a more attractive price point than SSDs. “There will be more real-time applications that are doing AI or analytics on the fly on video or other data streams but the question is what many of these users will do with all of that data they collect. There is value and, in many cases, they are not sure where it is or when it happens. Being able to go back, even offline or during non-peak times, and find what might not have been obvious is of enormous value in retail, security, manufacturing, and countless other industries.”

Bergey says these use cases are why there is a resurgence in interest around cold (or colder) storage, even among the cloud builders. As machine learning workloads continue to grow, coupled with yet more sophisticated  standard business intelligence and analytics, this will keep disk afloat for the long foreseeable future. Data volumes are not expected to shrink in any industry, after all. This bodes well for disk as well as the other tiers in an increasingly complex storage stack.

Bergey will be talking about why, where, and how HDDs will continue to matter at scale at The Next I/O Platform event in San Jose on September 24. We hope you’ll join us for a day of in-depth live discussions about technical trends in storage in the context of end user requirements. Our thanks to Western Digital for being a Gold Sponsor of the event.