Is there better living through Flash and Hybrids?

There has been a tremendous amount of hype around all flash and hybrid storage solutions this year.  New Dell™ EqualLogic™ new PS6210 flash arrays now offer significant performance improvements, but you may be considering  the best way to reap these benefits in your real-world EqualLogic environment.  Or if you are still evaluating flash solutions you may wonder is this going to significantly improve my datacenter.

As current EqualLogic owners have evolved their SANs over time to include several generations’ arrays often with different drive types, RAID types and even 1Gigabit / 10 Gigabit “hybrid network” SANs, I regularly get questions about what new EqualLogic member they should add next.  Typically the next step is looking at their SAN HQ files, identifying performance hungry workloads and understanding what changes or new workloads they anticipate having over the next year or two and then a plan is derived.  Having the opportunity to work extensively in the lab with the latest EqualLogic PS6210 hybrid and all flash arrays, it is clear that there may be some new opportunities to explore with the performance provided by this platform that can better extract the performance benefits of flash.

Hybrids arrays that are part flash and part spinning drives are the “value” point compared to full SSD based units and have part of the workload in SSD.  This can be very efficient if the “hot” workload fits in SSD, and can quickly adapt to changing conditions or new applications.  Of course the proportion of the data on spinning drives, will get spinning drive performance, so the question of sizing your workloads, and in particular the hot or warm proportions of the workload size compared to total volume space consumed.

Getting back to EqualLogic fundamentals, multiple members (arrays) in the same pool have virtualized volume pages spread proportionally to those members.  Each member then contributes part of the performance, using the incremental processing power, cache and network bandwidth provided by each Peer Storage array.  Looking at the hybrid array use case, and assuming that the workload is tiered, the potential performance boost for workloads that can directly migrate to flash is most symmetrical with like members in a dedicated pool.   Multi-member hybrid arrays pools are even more effective when tiered workloads are shifting since each member can directly promote hot workload pages to SSDs.

If you need the IOPS and performance for all of your data all of the time, “pure” PS6210S SSD pools give shifting workloads the most deterministic performance and now are cost comparable to the equivalent number of spinning drives it would take to delivery that same performance.  Seems intuitive that “all in” cost of ownership should be lower over time from footprint and power/cooling savings.

Even though EqualLogic has various automating load balancing tools to optimize mixed multi-member pools, the symmetry of scaling identical flash enabled members in a dedicated pool (eg: PS6210XS or PS6210S) is a simple and powerful  solution to consider for your highest performance workload needs.   A 6210XS is equivalent in capacity to two PS6110XS.    Additionally, if you can deploy in an existing group, create a dedicated pool, and migrate workloads one at a time to the flash enabled pool, watch the work load self-optimize over time (if it is a hybrid) you have an opportunity to see how much performance this workload really is asking for and can evaluate what other performance constraints there might be either in the network or server infrastructure.

Maybe this is the equivalent to a workload all-star team tryout, if that analogy makes sense, or workload psychology counseling to understand the volumes deep down IO desires.  Using SAN HQ to see how your high, medium and low workload tiers increase in size for each incremental workload, noting before and after IOPS, latency changes, queue depth, and other parameters gives a method for a better understanding of your environment.   Knowing more should be better than less.  Is that living better? 

So consider this dedicated flash enabled pool approach the next time you take your new PS6210XS or PS6210S array out of the box. For more thoughts on mixed member groups,  reach out to me with your thoughts on workload performance in your flash environment and  follow us on Twitter and Facebook to find the latest storage news.

About the Author: Jeff Junker