With the drought here in California, we replaced our grass lawn with drought tolerant plants. It requires a lot less water, but the best thing about it is that we have a new patio to hang out on and watch the world go past.
A few days ago I was smugly sipping a Quivera Sauvignon Blanc on our new patio, looking at our drought-tolerant garden and thinking about posting on “green enterprise storage” – a concept that always seemed like a stretch, considering the massive energy drain and short life cycles of these machines (~ 3.5 years). Even the comparatively small enterprise storage systems I used to work with at EqualLogic and StorSimple used a lot of power and generated a lot of heat. The much larger 3PAR systems I worked with drew massive amounts of power and were anything but green, even though they operated at higher utilization rates than most of their big gladiator-class competitors.
Enterprise storage is designed for hard use and it tends to get exhausted in short order. Organizations depend heavily on their enterprise storage systems and have little motivation to take chances by extending their longevity. No amount of greenwashing is going to change that dynamic.
While green enterprise storage is not exactly credible, the concept of sustainability in enterprise storage is. Sustainability is not an assessment of a product’s environmental impact as much as it is a long-term approach to reducing resource consumption and undesirable waste. In other words, the enterprise arrays used by a business might not necessarily be “green”, but the IT organization can have a goal of becoming more sustainable over time. When you see something that is so obviously wasteful – as enterprise storage is – it isn’t difficult to believe that progress can be made.
Flash storage is the game changer for sustainability
The undisputable champion of sustainable enterprise storage is flash. Flash has changed the trajectory of the entire industry and everybody involved is developing products and strategies to exploit it. While most of the focus has been on performance, there are clear cost and sustainability wins too. For starters, flash SSDs consume less energy and run cooler than disk drives, things that are key to lowering TCO and improving sustainability. Flash SSDs also wear out more slowly than disk drives because they do not have moving, mechanical parts. Even in hybrid arrays combining flash SSDs and disk drives, the disk drives are accessed far less frequently, reducing the heat they generate. Arrays that require far less energy for cooling over their lifetime improve sustainability.
Arrays that last longer and necessitate less frequent swap-outs do too. It is not evident across all vendors yet, but the warranties of flash-based arrays appear to be longer than non-flash arrays and the expected life cycles of flash-based arrays will likely prove to be longer as well, adding years to technology refresh cycles. When this trend is realized throughout the industry it will be another flash-based boost for sustainability.
It’s not clear to me what the manufacturing, distribution and end-of-life waste elements are for flash SSDs and disk drives. Perhaps that is something that will come to light in the future to help guide further discussions and comparisons of disk and flash storage.
The synergy of virtualization, consolidation & data reduction
Considering that data is stored under the direction of the operating system and hypervisor, there is a clear synergy between servers and storage, including the potential to improve sustainability. It follows that improvements generated by servers can be compounded by improvements generated by storage. For example, combining server virtualization and consolidation with data reduction in storage creates a very efficient stack, as illustrated below:
Many VMs are consolidated onto a much smaller number of physical machines, which use a single enterprise storage array to store data (represented by the steamroller). The array employs data reduction to eliminate statistical redundancies and duplicate copies of data that exist across all the virtual machines.
In the same way that virtualization and consolidation work hand-in-hand to improve enterprise storage sustainability, data reduction and flash-based storage are similarly aligned. Prior to the availability of flash-based storage, virtualization experts warned that applications could become starved for IOPs if too many VMs were accessing data on a single storage array. In other words, the scarcity of IOPs was limiting VM consolidation ratios – and further improvements in sustainability. Fortunately, flash-based arrays provide an abundance of IOPs, significantly expanding throughput and multiplying VM consolidation ratios several times over. It is still possible to oversubscribe a storage array with virtual machines, but the point is that flash-based arrays can support many more VMs than non-flash arrays. Increased VM density equates to fewer arrays purchased, less resources consumed and less waste at the end-of-life. When you factor in reduced energy consumption and longer array life-cycles, sustainability is increased even more.
The sustainability benefits of deduplication improve even further when similar VMs are aggregated together on a single array. For example, using a single array for a large number of Windows Server VMs creates an environment with a great deal of data commonality, where each additional VM added to the array has increased overlapping data that is deduplicated thereby consuming fewer array resources than the VMs that preceded it.
Small improvements matter
Enterprise storage arrays need to provide high level of performance and availability, which means they will never become sustainable in the way that organic farming is. That said, there are well-defined and achievable ways to improve the sustainability of enterprise storage using flash-based and data reduction technologies. There are a wide range of products and prices, from server software solutions, to hybrid arrays and all-flash arrays. The good news is that improving enterprise storage sustainability is easily done without restructuring budgets by replacing end-of-life non-flash arrays with more sustainable flash-based arrays that cost approximately the same, or even less than the arrays that they are replacing – and have lower operating costs. As they say, YMMV and there are many options and ways to proceed.
Disclaimer: The company I work for, Tegile Systems, designs, manufactures and sells both hybrid and all-flash enterprise storage arrays.