In recognition of Earth Day, we thought we’d publish a post on a certain “green” topic that we’re passionate about around here—the power and performance efficiencies achieved by using SSDs in enterprise servers. As you know, Micron has a lot to say on the topic, so we decided change it up a bit and bring in a longtime storage industry veteran to provide a different perspective. (BTW, we’ll have more to say on Micron SSDs in the enterprise here soon ... stay tuned.)
While at Storage Networking World last week, we had the chance to meet up with Ray Lucchesi, president and lead storage analyst with Silverton Consulting, as well as blogger extraordinaire for RayOnStorage.com. We asked him to shed some light on the role of SSDs “greening-up” the data center:
Thanks for talking with us. To kick off the discussion, let’s look big picture at the challenges facing data centers today. Could you provide a little insight for our readers on what the top issues are for data center managers?
I think the problems facing data centers today center around 3 main themes:
- Doing more with less: Mainly this is due to the realization that all business functions need to provide value to the bottom line but recent economic troubles have accelerated this trend. The emergence of server virtualization is just one manifestation of this trend.
- Being more responsive: Businesses today need to respond faster to opportunities in order to survive, and this need has been accelerating over time. Opportunities pass by quickly and often can be very profitable, but if you don't capture them your competition will certainly be happy to try.
- Reducing energy use: Businesses need to reduce energy consumption to deal with rising energy costs but climate change is yet another reason to do this. Some data centers have limited ability to increase power at their present locations and as such, cannot add new equipment without shedding equivalent energy use elsewhere.
How do you see solid-state drives playing a role here?
SSDs can help with many of today's data center challenges. First, SSDs provide higher performance which allows companies to better respond to opportunities when they appear. Second, SSDs use less energy on a performance and per unit basis and thus, can reduce power consumption for any given workload. Finally, hard disk drives are often over-deployed in order to obtain better subsystem performance, dividing storage workload over more spindles. But because SSDs can perform so much better than disk drives, data centers can often reduce their spindle counts dramatically just by deploying SSDs.
What has been the primary barrier to adoption of SSDs in the enterprise? It seems the power and performance benefits are obvious.
SSD cost is a significant barrier to adoption in enterprise data centers. High $/GB cost makes justifying SSDs much more difficult. Also, application performance gain is often hard to predict ahead of time which makes SSD return on investment calculations even harder to believe. But once you have passed those hurdles, deploying SSDs today takes analysis to determine which data to place on them to optimize data center return. Sophisticated storage subsystems are starting to introduce migration capabilities which automatically and non-disruptively migrate data to or from SSDs to optimize performance. For example, IBM's Easy Tier and EMC's FAST both provide data migration between disks and SSDs to maximize storage performance.
Have you performed any comparative analysis on real-world usage of SSDs in the enterprise, i.e. power savings and/or performance improvements? What were your findings?
There is plenty on my blog about SSD performance and energy use. Specifically, one post I wrote last year reported on SSD vs. Drive energy use which showed a significant difference in peak versus nominal energy use between hard drives and SSDs. This energy use difference was insignificant for SSDs but was very significant for hard drives. As such, data center energy use should not spike as much with more demanding workloads when data resides on SSDs. In addition, every month I report on storage benchmarks such as SPECsfs(R) 2008 from the Standard Performance Evaluation Corporation that often show significant performance advantages from the use of SSDs or flash based subsystem caches.
What are some trends you see in the green IT movement?
There is interesting work going on to provide more efficient cooling. For example, I saw a specially designed rack enclosure last year that was optimized server rack air-flow/cooling. Also I recently read of data centers deploying new cooling capabilities to reduce energy use such as, using night-time power to freeze some material and then using that material to cool their data center during daylight.
Also many data centers are moving to server virtualization technologies which allow them to boost utilization of server and other IT infrastructure. Systems such as VMware and Microsoft's Hyper-V allow multiple application workloads to co-exist on the same physical server increasing utilization significantly.
Finally, the whole trend to using less energy is moving from the consumer space into IT. Processors, networking and storage are all on an energy diet. It's common nowadays for storage companies to tout recent power consumption reductions that come with the latest versions of their subsystems. Blade servers and newer processor chips also announce energy savings along with performance improvements. Similarly, networking follows this trend by providing more bandwidth while at the same time using less energy.
Consequently, IT's energy use is dropping overall as well as on a per application basis and thus, provides for a much more sustainable data processing environment. Such trends should enable data processing to grow while lessening its energy and carbon footprints over time.