It’s been a while since my last blog post, however it’s been a very busy year with travel and taking on a new role at EMC (or soon to be Dell) as a technical specialist for XtremIO.
I joined EMC around 10 months ago (time really flies) for one reason and that was to be part of a disruptive storage technology….XtremIO.
Traditional spinning disk technology has not changed in the past 20+ years. 15K drives were introduced in 2000 and physics will not allow disks to get any faster.
Now I’m not saying that disk is dead (like certain other vendors) as it still has a place in the datacenter for unstructured data, backup/archive, big data etc.
Having spent many years in the storage market the main challenge with spinning disk is latency. You have to throw a lot of spindles in an array to ensure application response times are consistent. This is a very expensive exercise and leads to poor utilisation of capacity, datacenter space, plus high power & cooling requirements.
Like many others, XtremIO is an All Flash Array. This is where the similarities end!
Solid State Disks (SSD’s) & other flash media is very fast….most of you already know this as you have them in your laptops and smart phones.
Whilst speed and IOP’s are important it’s not the most important factor. In fact, flash will give you way more IOP’s that you’ll probably ever use!
As I mentioned before, latency and application response times are the most critical and the key with latency is to be consistently low.
Flash storage is an enabler to deliver consistent low-latency, however the storage architecture you build around it is the key to success or failure!
Most vendors (including EMC) started out by adding flash as a front-end cache to accelerate reads/writes on existing disk arrays, we then saw the next generation of hybrid-storage arrays/appliances that were purpose built with both SSD’s and disk. Around 2010/2011 the first All Flash Arrays started to appear on the market.
This new generation of All Flash Arrays (AFA’s) came along with software that was optimised for NAND media. I won’t go into the details and nuances of NAND flash as there are plenty of other sites that cover this very well.
The major drawback with these new AFA’s is the fact they were designed using active/passive/standby dual controller architectures. Nothing radically different from previous arrays. This design approach is fine for spinning disk arrays as the performance characteristics of the media is much lower, but with flash media it’s a whole different ball game.
Dual controller architectures can very quickly become a bottleneck for performance especially when you add additional capacity. This type of architecture is commonly known as ‘Scale-up’.
So, what happens when you hit the limits of the storage controller? You can either move workloads off to somewhere else or buy another AFA and have seperate islands of storage (sounds no different to what we did before, except the media is different!).
A certain vendor will offer to swap out controllers, however the devil is in the details. I’d strongly recommend you read the T’s & C’s.
What attracted me to XtremIO is that it’s different to other AFA’s. The guys in Israel who designed the platform (before EMC acquired it in 2012) really knew their stuff when it came to flash. Rather than just following everyone else down the path of a dual controller architecture, they chose the hard path and built a true multi-node ‘scale-out’ cluster. For more information on this see the following White Paper: Technical Introduction to XtremIO
Moving on from performance and the importance of architecture, AFA’s must be able to do other stuff. Being fast is just the beginning.
Data Services and application integration are what makes any array truely valuable to a business.
Deduplication and compression are pretty much table stakes for AFA’s. Snapshots/Clones less so and milage will vary.
Copy Data Management is one of the hot areas that XtremIO is focussed on. CDM allows application owners and developers to create multiple copies of key datasets in a consistent, fast and space efficient manner without impacting the performance of production on the same AFA.
As the latest StarWars movie was released last month I put together a themed video outlining XtremIO Copy Data Management. Enjoy!