Nothing sends me around the bend faster than when a vendor lies to me. Now I realize that “lie” is a strong word and I shouldn’t use it in accusatory speech or in the written word. I also understand that in areas of fast paced technological development there can be genuine cases of misunderstanding. However none of the aforementioned circumstances apply to vendors who knowingly and blatantly misrepresent their products and features. I think somewhere about the time I attended Kindergarten I learned this type of behavior was not only wrong but completely socially unacceptable.
So why then do companies like EMC, HP, IBM and others market their Active-Passive (A/P) arrays as Active-Active (A/A)? I actually have no idea but I will say that although I have the utmost respect for many of the folks in their engineering, R & D, and field teams I think the folks in their Marketing organizations are nothing but a pack of liars out to take advantage of the unaware.
Once upon a time I had occasion to be at Tech show and was casually talking with some of the staff at vendor (name withheld to protect the innocent) booth. During the conversation the booth staffer began to elaborate on how their latest generation storage array had all these new cool features, enhancements and amongst other things was A/A. Really? Now I admit I’m not an expert in practically anything but I do know a little something about storage and what constitutes A/A verses A/P. So I ask the intrepid marketeer how it was that this Nth generation, that came from a long line of arrays in this array family, was suddenly A/A given all previous generations were A/P.
Oh, no he tells me, they’ve always been A/A, I must have been misinformed all these years. Ok, it happens to the best of us, please tell me more. Well, you see the A/A nature of our platform inherently gives it the ability to serve up LUNs from both Storage Processors (SP) at the same time. Wow, that is simply amazing, possibly even revolutionary now that I think about it…are you kidding me?
I was able to get control of myself just before I asked if he was mildly retarded or just storage stupid but not before I had to ask a couple of what I admit in retrospect were unfairly complex storage architecture questions. I began by asking if their array was A/A then what is an A/P array do and how was theirs different and followed up with if all the paths to the LUNs were accessible simultaneously? Well, no all the paths weren’t active because after all who would want that?
That was it, I couldn’t take any more and explained that A/A actually mean that all paths through the SPs were active, all the time, hence the origin of the phrase “Active-Active controllers.” I further explained that when you have an Nth generation system where only some of the paths are active due to the fact that you couldn’t access the LUN through the other controller unless you trespassed the LUN, it meant that it was in fact an A/P array. He was absolutely incredulous and proceeded to call over an Engineer who would attempt to brain wash me, I mean educate me further in the Jedi ways of storage.
The Engineer walks over eager to assist and says that I was in fact correct but that they choose to define A/A as meaning you can “actively use both controllers at the same time, just not with the same LUN, of course.” Well that certainly clears things up, I mean after all, let’s not let little things like commonly accepted definitions and facts get in the way of good marketing. In fact, I think its a great idea that vendors just make up whatever they want and tell prospective customers whatever they think they want to hear.
I’m officially done ranting about this issue (probably not) however I do want to point out that there are a number of storage vendors grossly misrepresenting their product’s features and capabilities. If you are not well versed in the technology you are looking at, listen to what they have to say and ask someone you trust. If all else fails, ask me. It’s not that I’m any more likely than anyone else you may have asked to know the answer but at least you’ll know I won’t tell you your new Nth generation array is A/A if it is not.
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2 comments:
Where are you actually getting your definition of active/active?
According to the Storage Networking Industry Association (SNIA):
active-active (components, controllers)
[Storage System] Synonym for dual active components or controllers.
dual active (components)
[Computer System] A pair of components, such as the controllers in a failure tolerant storage subsystem that share a task or class of tasks when both are functioning normally, but take on the entire task or tasks when one of the components fails.
Dual active controllers are connected to the same set of storage devices, and improve both I/O performance and failure tolerance compared to a single controller. Dual active components are also called active-active components.
Another similar definition:
http://searchstorage.techtarget.com/answer/Active-active-vs-active-passive-arrays
I actually did some searching looking to CONFIRM your views on this, but did not find much in the way of official published information by any kind of authority on the subject...
Maybe pick up a book called mastering VMWare. This book explains the difference between active/active and active/passive.
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