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By | Bryan Betts 11th June 2014 16:29

Do you really have to slash and burn to upgrade your storage?

Software defining the future

Whether it’s new storage architectures, software defined networking (SDN) or cloud computing, the assumption is you start with bucket-loads of cash and either a slash 'n' burn approach to your existing set-up or develop a green field site into which you can install the latest all-singing, all-dancing technology.

But what if this is actually a misconception? What if it is possible to implement SDN or Flash storage gradually, perhaps as an overlay on an existing infrastructure, and in smaller organisations?

According to Tony Lock, programme director with market research company Freeform Dynamics, it has to be. “Very few organisations are going to throw out all their old equipment and replace it – I don't think you're going to see much of that,” he says. Yet that embeds inefficiency, both in resource and time usage, especially on the storage side where new applications have been added in silos.

“Managing lots of silos is very time-consuming, plus you have a lot of unused storage,” he says. “The problem is that IT generalists are rushed off their feet, so they don't have time to learn better ways of doing things. They need the vendors and more usually the channel partners to advise that they don't have to rip and replace, and that they can move forward with what they’ve got. And then show them how.

“Compared with putting stuff into the cloud, SMBs are much more interested in making use of what's already in-house. What most organisations need is sensible advice – here's where you are, here are your options, here's how to move forward. But do the resellers know the options? I suspect not – the biggest problem is the channel. It's a huge educational job.”

For storage, one of the key technologies to look at is storage virtualisation. This could use software such as DataCore's SANsymphony or a hardware gateway such as IBM's SVC, for example. The concepts are the same: the available physical storage is aggregated into pools of blocks and the controller then draws on these pools to construct new logical or virtual storage units that can be assigned to servers and so on.

As well as the ability to construct virtual volumes of any size, or indeed of variable size (for thin provisioning), the controller can also perform tasks such as mirroring, replicating or tiering your storage volume below the surface, transparently to the app. In addition, because it aggregates and pools existing storage systems, it also pools free space. This means there is no need to leave empty, wasted space on every physical system just in case that application needs it for growth.

This kind of technology has been around for many years but when it emerged the market wasn't really ready for it. It was a solution in search of a problem. In effect it is software-defined storage. You can see analogies with SDN, both in their development and in the way that what's finally making them practicable for the mass market is the increasingly complex demands put upon IT and the development of advanced automation and orchestration technologies that need these highly flexible underpinnings.

Those automation and orchestration techniques can also make it easier to add new technology alongside an existing infrastructure without going the whole hog towards infrastructure virtualisation, says Jay Prassl, VP of marketing at Flash storage developer SolidFire. He argues that by enabling users to self-serve, systems such as SolidFire can be used to deploy new storage services without incrementally increasing the admin workload.

Hybridising the network

As with storage virtualisation, not everyone needs or can use SDN. In addition, the immaturity of SDN technology means we do not really know what the benefits will be. Indeed, the message from early adopters and vendors alike is that the cost savings are overhyped and that the real wins are more likely to be operational.

"SDN is the most mature of the SD movements, but it is still pretty immature, and there’s not a lot of people out there doing it," says Ovum analyst Roy Illsley. "SDN has got great benefits, but it's causing people to ask how on earth to do it. That's why a green-field is easier. The technology looks good, but it's not mature enough and the smallest deployment would be your smallest site.”

He adds: "SDN has all these positives, but we won't find out what it's really capable of – or what the drawbacks are – until we are actively using it. We are at a tipping point now though, with all sorts of systems going from physical to virtual.”

Not everyone will need SDN though, says David Noguer Bau, head of service provider marketing at Juniper Networks EMEA. He thinks it’s good for people who make a lot of changes or need agility in their networks, or who need network segmentation, or anyone building a multi-tenanted architecture. "Small companies tend not to play with their networks, which leaves large enterprises. Although it could also be a 10-person service provider, say, or a software developer that needs test environments set up quickly,” he says. The advantage is automation. It brings network operations to the same level as virtualised computing.

"Then it's about the talent they have – you need people with both IT and IP knowledge to help with the selection of tools and so on, and those people can be hard to find. With SDN, the network and IT managers need to agree on what the network needs and what the applications need. They have to sit together in this world, with a deeper level of agreement and understanding. In a way, the [SDN] controller becomes a gateway between the IT and networking departments."

This could also give SMBs an advantage over their larger and slower brethren, particularly if their size and relative agility makes it easier for them to absorb the network-as-a-service concepts and methodologies inherent to SDN. The same goes for SMB networking and IT staff – they will often be closely integrated and will sometimes even be the same people, making them ideally placed to bring these two otherwise warring worlds together.

It could also be an opportunity for system integrators to put together a datacentre-in-a-rack, with SDN and storage virtualisation providing the automation and orchestration frameworks alongside the rather better known hypervisor-level tools for virtual machine migration and suchlike. “The type of organisations we deal with prefer a more integrated approach. They won't contact vendors directly. It could be an opportunity for system integrators to package it all up,” says Noguer Bau.

“There are several approaches - we have a controller model with our Contrail available licensed or as open source [OpenContrail]. Normally you'd package it with the OpenStack orchestrator. The advantage is that the customer might already have switches with VLANs and so on, so now they gradually install OpenStack, integrate it with Contrail, and it will create an overlay.

“Contrail will look at the servers they have and install a virtual router in each one. Then all it cares about is when OpenStack creates a new VM, and when it does it will provide connectivity with the other virtual routers.

“It's a layer of virtualisation, not using VLANs and not dependent on the hardware. It starts and ends in two servers. You can run an entire data centre over one VLAN, all at layer three and using any switches because we don't interact with the hardware. It creates a sort of private virtual network, and then creates VPN tunnels within that.”

Virtualising the tomayto

Of course, SDN – like storage virtualisation – means different things to different people, and the industry has come up with at least three different ways to implement it, depending on how much you want to involve the hardware. At one extreme, Cisco is building programmability into its big switches, while at the other virtualisation specialists have developed overlays where a virtual SDN sits in a VLAN on the network and in virtual routers on the server hypervisors. In between are the more hybrid approaches such as OpenDaylight, using OpenFlow to control and direct packet flows on the physical network.

Khurram Khawaja, Alcatel-Lucent's enterprise core and data centre product management director suggests it might be better to back off and take a broader look. . "SDN is more of a methodology, an architecture and approach for solving the problems that enterprises typically cannot solve," he argues. He offers the example of virtual machine mobility in the data centre – you can create a VM very quickly now, but if the network can't adapt there is still a lot of manual reconfiguration required.

"One of our North American healthcare customers was maintaining a really long script to do VM mobility, which was a really tedious process and meant it could take weeks to move a VM, rather than minutes," he continues. "Now with SDN they can do it in a few clicks.".

He adds: "The way we see SDN is quite a bit different from network automation – SDN is the promised land where the network responds to application automation and provides feedback on what is and isn't possible."

On that basis, an SDN is indeed the network equivalent of server and storage virtualisation. It gives you a set of network objects, such as virtualised switches, routers and firewalls that can be deployed in a highly automated manner. In this, it resembles network function virtualisation (NFV), which is the process of running more and more network services from firewalls and intrusion prevention systems to load balancers and WAN optimisers as virtual appliances rather than physical ones.

However, whether it is servers, storage or networks, simply moving from physical to virtual achieves little beyond the initial reduction in power and rack-space consumption if you still have to manage it manually. It is only once you add some dynamic intelligence to a virtualised technology, linking that automated deployment to the needs of the business that you can start to see wider benefits.

In addition, networking is infrastructure and it is inherently harder to develop and deploy innovative infrastructure compared, for example, to innovative consumer applications or even enterprise storage, says Neela Jacques, executive director at the OpenDaylight project, which is developing an open-source SDN framework. He contrasts the way that consumer app start-ups can be based in San Francisco, Berlin or London, and run by younger people with relatively little history in technology, whereas an infrastructure start-up still needs deep subject knowledge and will probably need to be based somewhere more technical.

"There's tons of storage start-ups – the reason is you need knowledge of the technology and the background, but as long as you can find something you can do better than everyone else and you can persuade some IT managers to let you in, you can grow from there," he says. "You haven't seen that level of start-ups in networking because you don't have the same dynamic. We've tended to have one big vendor and some second places. It is inherently harder in networking to find a corner of the data centre and say 'My innovation goes here'. The network is fundamentally connected and interoperable, and the cost and risk of choosing the wrong technology in networking is far higher than in other areas.

“Having a green field lowers the risk. You can start from scratch, standardise on certain technologies. There are ways for SDN to come into brown field sites though – for example, traffic shaping is one way you can add some level of programmability." He adds that one advantage of the open source approach is that it is pretty cheap to evaluate and implement – it just needs a VM to run the OpenDaylight software.

So, if IT agility is important to you, or if you are having difficulty keeping up with change requests, SDN and storage virtualisation could be the answer. Whatever the size of your organisation, if the network is big and busy enough to need network and storage administrators, it is probably big and busy enough to benefit from virtualisation.

You still have to know your infrastructure and ask the important questions though, warns Tony Lock. “You have to know what you've got in your organisation,” he concludes. “Do you know where it all is, what's on it, and what are your business rules on looking after it? Then it's what can we do, what risks are we willing to accept? You have to know where you are in order to work out how to use it more effectively.” ®

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