Stretching VMware NFS Datastores Across the WAN—Simplicity and Elegance


When is technology great?

What makes a great bit of technology? Its age? Function? Relevance? I would put forward the idea of everyday adoption. Take the television, the fridge, and the car as examples. They are technological marvels that we use, and expect to use, without a second thought. You don’t contemplate the wonder of the chemical reactions in a combustion engine or the cooling elements of a fridge. When you use them, you just open the door and get on with it. These technologies were not always comfortable, but they have long since become a part of everyday life.

What you are most concerned about are the “results”: getting to work on time and keeping your food fresh. The technology that played a part in it has its role, but it’s secondary to the results it delivers. And I would say that is what makes a great bit of technology, when your focus can be on the execution, delivery and results that the technology enables, rather than fighting the fridge or the car to get anywhere!

And we can move this out of the home and put it into the work place with the personal computer. You  sit down, start typing, and that email is sent without a mention of the tool that enabled you to type it.


Enterprise IT

So how does this translate into the enterprise IT environment? Riverbed has been providing this kind of “everyday adoption” for WAN based workloads for the last 10+ years. With Riverbed SteelHead appliances, applications have been working over low bandwidth and high latency links without the user even aware it is happening. Just like the car, Riverbed SteelHeads have become a “secondary technology” in the role of IT delivery over the WAN. Delivering working and responsive applications and services from the data center, or cloud, to the end users on remote sites.

And now that idea has taken a step forward with the ability to provision and manage NFS datastores for VMware. Datastore delivered anywhere in the world, from the security of the centralized data center. At first pass that may not be the most exhilarating news any IT guy has ever received. After all NFS datastores and VMware is a bit like hearing that fries go really well with a burger. What should get things moving though is that these NFS datastores can be provisioned literally thousands of miles away to ESXi hosts. From the data center, they are capable of working at LAN speed even when disconnected from the data center for whatever reason.

So what we’re really talking about is having centrally managed and provisioned NFS datastore for VMware from the data center. Whether for ESXi hosts in the next rack down, ESXi hosts in a manufacturing facility on the other side of the world , or ESXi hosts on a ship in the middle of the Pacific Ocean over a satellite link. All can deliver applications and services as if they were meters away from the users, which technically they are!!!

NFS isn’t new, that’s not great! 

Or is it? Think about it. As a VMware admin, storage and datastores play a big part in the planning and deployment of a VMware estate. Would you rather spend hours figuring out how it’s all going to hang together or simply know that you’re going to need X amount of space to make it fly? I’d go with the latter every time. This is the beauty of NFS and it not being new, it’s a very predictable, very scalable, very robust protocol that just does what it does well. Going back to that notion of a “secondary technology”, you don’t want to be wondering how the protocol negotiates a connection, you just want an amount of storage for your VM’s here, now, and ready to build on.

And Riverbed SteelFusion has released that NFS predictability, scalability and robustness from the data center and made it available over the WAN. By using SteelFusion’s unique ability to do differential data transfers of only the data an application needs, NFS datastores terabytes in size can be projected in seconds over links with the equivalent of 500ms latency and 2Mbps of bandwidth. By only sending the data that is needed, you never have to wonder if the vmdk file hundreds of GB in size was copied over a weak line and hope it doesn’t get interrupted before it finishes. SteelFusion will send what you request, when you call for it.

The “What if’s and how do I…”

What if the link does get broken during the transfer, then what? You can preload the NFS datastore in the data center if you need to. All your VM’s fully populated and loaded onto the SteelFusion Edge (SFED) device for when it lands at its final destination. Two power cables, four network cables, and all the VM’s you loaded earlier are up and running in minutes. Any write or modify of the data is then synchronized between the SteelFusion Edge and the storage array.  This makes sure there is a secure copy in the data center at all times, eliminating remote data backup concerns.

And if any data transfers, either way, are interrupted due to an outage of any kind? The SteelFusion Edge device will just hold onto what it has until it sees the link has come back up. It will then start again automatically from where ever it go to.

What if want I expand the NFS Datastore due to onsite data growth? Expand it on the storage array, check it has been picked up by the SteelFusion Core, and voila it’s expanded it on the ESXi host on the SteelFusion Edge.

What if I manage hundreds of remote sites – how do I scale this? Through the SteelFusion Core, a single pane of glass that allows for the management and monitoring of every single SteelFusion Edge deployment in an environment. Mount, map, and protect all NFS exports from one place no matter where they are deployed in the world.

So is SteelFusion a “Great Technology”? 

As an enterprise architect for a vendor “of course it is, what are you waiting for!!!”, but as a realist it’s a bold statement that only someone else can decide. Over 1000 enterprises have chosen this path, and many well-known companies continue to standardize on the SteelFusion approach. What I can tell you personally, for one of my NFS customers with whom I engage regularly, it absolutely is. His headaches of managing disparate servers, pockets of aging storage, and ever failing backups that are 100’s and 1000’s of miles away, have now all been condensed down to the data center where he is based. SteelFusion obviously plays a part in his daily life, but his primary focus is on his data center NetApp and how he’s going to get more storage for all the remote projects that can now be deployed efficiently.

Perhaps the better question should be; could SteelFusion be a great technology for you? Would pulling all your data and storage back to the data center make your life easier? Is having every single backup in the data center better than having them dispersed across the globe? Would having the agility to push and pull applications over a WAN link from one centralized location speed up business results?

NFS is a great technology and with a little help from Riverbed’s Software Defined Edge solution, it can be made even greater, projected out to quite literally anywhere in the world.

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