Caching has become a logical first step in accelerating application or virtual server performance, so caching software is a must-have. Each company must offer at least one caching solution along with access to other independent suppliers. Many server-side caching solutions are becoming more integrated with hypervisors like VMware to handle virtual machine movement, and we expect this integration to help overall adoption.
We're also seeing a trend toward increasingly advanced caching software. Several acquired vendors offer technology that either creates a global cache pool by aggregating SSD capacity in individual servers or creates a dedicated SSD tier from that aggregation.
Drive Form Factor Drives
Currently more money is being spent on drive form factor drive manufacturers than PCIe SSD manufacturers. Despite its latency disadvantage compared to PCIe SSD, drive-based flash has the advantage of easier server integration and protection (RAID). With the performance gap narrowing thanks to 6- and 12-Gbs SAS, PCIe vendors face a challenge explaining the advantages of PCIe-based technology. Those advantages clearly exist, but if they can't be explained, PCIe SSD risks being utilized by the performance fringe and missing the mainstream data center altogether.
[ What does "software definition" mean for flash? Read Should You Use Software-Defined Storage? ]
Own The Flash Controller, Not The NAND
Much has been written about the advantages of owning the NAND manufacturing process and integrating that knowledge into advanced flash controller technology. Unfortunately, little of that theory has translated into a reality that IT professionals will buy into. What is clear is that innovation and differentiation around the flash controller is more important.
For example, flash controllers can now modify the flash programming charge as data is being written, to soften the charge under non-duress situations. This extends the life of the underlying NAND. That's just one example -- a complete list of the various flash controller differentiators would be too extensive for this column. Flash controller developers are not standing still; several are working with deduplication API developers to integrate storage efficiency technology directly into their controller to reduce costs and increase durability.
What Does This Mean To Joe IT?
Tracking industry movement may be interesting for analysts, but what about IT professionals who simply need to get the job done? The first thing to keep in mind is that the caching software you buy today will probably soon end up with a different logo. I know of no shorter lifespan than that of a caching company. That should not be major concern, though; caching is too integral to the acquiring vendor's SSD strategy for the software not to continue improving after an acquisition. Just expect that your caching vendor will likely experience a name change.
Second, review the above list of requirements. These companies are making large investments for a reason. The combination of caching and a drive form factor SSD that has internally developed flash controller technology seems to be the way to start moving to the all-flash data center.
Finally, PCIe SSDs and shared storage system vendors need to better explain their advantages (and maybe reduce their pricing too).