Busting the myths of the data centre Gavin McLaughlin, Solutions Development Director at X-IO Storage examines power efficiency in storage
In all walks of life, not just the IT industry, history is littered with common misconceptions that, through deliberate misdirection, false marketing or just plain old hearsay become common “facts” that just simply aren’t true.
One of the latest doing the rounds is the almost hysterical shouting from the rooftops by flash memory (often referred as “AFA” – All Flash Array) vendors that solid state drives or flash modules use much less power than traditional hard disk drives. Whilst this may be the case with some disk drives and some flash modules, again much like in real life, this can sometimes be true, however it’s not right to make a general statement because it’s not factually accurate.
When it comes to data centre power consumption, which is increasingly in the spotlight the marketing noise from many AFA is particularly loud. It can be easy to be seduced by marketing statements from some storage vendors such as “requires only 10W per Terabyte” and perceiving it to be a highly efficient array. It’s only when you delve deeper into the unit’s architecture to find that a 10TB array has two 2.5KW power supplies that you may smell a rat.
This is because they’re talking about the raw components rather than the entire storage solution. Whilst in some cases (but not all), flash memory needs less power than hard disk drives, you still need to drive them using reasonably meaty processors and some traditional cache memory to help accelerate writes. These all need power and when you couple these together and then add some not necessarily well-written efficient code, you can suddenly realise that the marketing statement was analogous to looking at the fuel usage of a domestic boiler when it’s merely running just the hot water and not the full central heating.
When used carefully and correctly, hard disk drives can actually be more power efficient, more reliable and even better performing than flash memory. The truth is that in order to address many of today’s challenges faced by organisations requiring enterprise storage, a “right tool for the job” approach is necessary. Hard disk drives are great for sequential workloads for example, whereas flash memory is great for smoothing out the bumps in a random workload. Only by carefully fusing both enterprise grade hard disk drives and flash memory do you realise the best of both worlds and be able to deploy true hybrid storage.
The real benefit though for organisations concerned about power efficiency is that the power and cooling requirements [of hybrid storage] are actually much lower than not only all flash arrays but also traditional enterprise storage.
Solutions that enable customers to deploy enterprise grade, real-time tiered hybrid storage are rare but do exist on the market, Using this sort of enterprise solution enables the performance boost of flash but at the more efficient price point of hard disk drive arrays. The real benefit though for organisations concerned about power efficiency is that the power and cooling requirements are actually much lower than not only all flash arrays but also traditional enterprise storage.
It’s clear that with the right guidance and using the right tools businesses can learn from enterprises that are making the most of the power in a datacentre, whilst not compromising on performance and reliability. With all the marketing noise in the storage industry right now, it’s very easy to believe some of the misconceptions being thrown around. Don’t be fooled by them. Instead, focus on digging deeper than just the marketing blurb. Find out the real facts and don’t compromise on performance. Otherwise you could end up finding out the hard way.