With thanks to Led Zeppelin for some great lyrics.

There's a sign on the wall
But she wants to be sure
'Cause you know sometimes words have
Two meanings

Since cloud computing has a bit of an identity crisis, and cloud storage is just starting to realize one itself, it should be no surprise to anyone that “cloud storage gateway” has more than one meaning. While they are  all a single market, implementation and deployment details make them very distinct products. In such a young market, differentiation is easy, even if selling your differentiation as a plus is not. Some vendors are already attempting to turn product differentiation into market segmentation – the upcoming Cirtas product, for example, is referred to by them as a “Cloud Storage Controller” because they believe that better defines their product, though they acknowledge that the market term “gateway” has taken on.

When she gets there she knows
If the stores are all closed
With a word she can get what she came for

Okay, so you don’t quite have that power, but all of these products do offer you a significant bonus in terms of cloud storage in the form of thin provisioning. For several years now you have had the capability to tell your server it had more storage than was actually dedicated to it, and if it ran over what was actually dedicated, more was allocated from a pool. The problem with this model is that you have to be certain you have enough storage to cover the worst reasonable case – what percentage of your servers might request extra storage over the weekend, and how much might they request. Weekend, month, year… Whatever your timeframe for buying new storage. The point of over-provisioning is that you’ll likely be oversubscribed, but you’re taking the risk that the oversubscription will never come due at the same time with one large calamitous bang. I wrote about this scenario and how virtualization has made the risk worse here.

Yes, there are two paths you can go by
But in the long run
There's still time to change
The road you're on

Enter Cloud Storage Gateways. First a bit about cloud providers… They scale up to as much as you need (as long as your payments are covering it anyway), and down as your usage goes down. I won’t say all of them fit this pattern because there are a bewildering number of players looking to make a name in this space, and believe it or not, F5 doesn’t pay me to ponder cloud storage or cloud storage gateways, they merely allow me to chat about it, but I’m not taking weeks researching all of this, more like hours. The big players do indeed scale up and down, only billing you for actual usage though.

Now that we have covered that for any who didn’t know, the cloud storage gateway handles the intricacies of dealing with various cloud storage providers, and most cache locally and encrypt on the way out.

Starting to see the silver lining yet? They give you thin provisioning limited only by how much money you’re willing to risk. The current model gives you thin provisioning limited by either how much you’re willing to pay to guarantee you have enough disk for the worst case, or the amount of risk you’re willing to take on. Cloud storage gateways navigate that mine-laden sea for you and guarantee that your servers will stay up as long as you’re willing to foot the bill.

Of course that doesn’t eliminate planning for you, but it does allow you to move the choke point up and down much more easily. You can eliminate the risk without a significant cash outlay, if that is your desire, as long as you know what it will cost you if your servers all start requesting more and more storage.

And it makes me wonder

(if you just went “Ooohhh Yeahhh-hah” in your head, take a moment to laugh at yourself, it’s healthy)

The biggest risk in cloud storage gateways is the one I mentioned in a previous blog. If they are scooped up by cloud storage vendors that suddenly remembered the lingua franca of enterprise IT storage is not SOA, they will surely limit your options on the back-end. One of the strengths of these products is that you can point one at two completely different cloud storage vendors and remind each that with a flick of a switch, you can be on the other one, so 48 hour response times are not acceptable. That benefit would almost certainly disappear if a cloud storage vendor bought up your cloud storage gateway vendor. Otherwise, the risk is not any larger than any other cloud solution.

Your head is humming and it won't go
In case you don't know
The piper's calling you to join him

Cloud everything is the buzz du-jour, and cloud storage with a gateway to make it appear on your network as a NAS is a good idea for tier three, and these vendors are all (I’ve only spoken to three, so “all” is a bit of a stretch) saying they’re getting traction on tier two also, which makes sense for a lot of tier two data. Either way, it’s coming your way, and you should consider if it has a space in your datacenter. The idea of truly thin provisioning is a huge one that even further removes you from the limitation of monstrous disk arrays.

And if thin provisioning with no subscription worries is on your list of things that would help you sleep at night, I suggest you go out and try…

Bu-uying a stairway… To (thin provisioning) heaven

And I won’t even get into what these solutions coupled with the automated tiering of ARX can do for you. That’s for another blog.

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