Unravelling network fabrics

Fibre channel

Although seemingly ahead of many of its competitors, Juniper is fresh to fabrics, its QFabric offering launched barely a year ago.

But for those with big storage networks, emerging network upstart Brocade has provided its Fibre Channel arrays for some time. It now offers solutions for the Ethernet needs of the rest of the data centre.

Cloud provider 6YS is one of the first in Australia to take on Brocade and is hoping promised developments to knit its five data centres around the country will soon bear fruit. The company’s chief technology officer Martin von Stein says the shifting demands of customers make a reactive approach to data centre management challenging.

“[6YS’] primary environment was already relatively flat; we were running a core-to-edge architecture but the main issue we had was bandwidth management,” von Stein says.

“We had great difficulties in ensuring we had the right amount of bandwidth in the right rack at the right time so we were constantly shuffling uplinks.”

Von Stein was attracted to Brocade’s guaranteed traffic scheduling to avoid blocks of data getting lost in the middle that’s destined for disk I/O, a problem that frequently leads to crashes.

He says 6YS had the option to rip and replace but decided initially to overlay the new fabric; it’s now backfilling the old topology with the new. But it was almost an accident:

“We came into the Brocade fold mid-last-year and we weren’t looking for fabric; our specification called for reliable 10GB switches. Brocade had a good price and features and in the first meeting they mentioned Ethernet fabric. It was almost an unknown to us; we went and did research and they gave us demo units to look at.”

A big advantage for 6YS is how redundant switches are bonded.

“You have two network interface cards but the switchgear fools it into thinking it’s one 20GB trunk – if a switch fails you are just reduced to 10GB; it’s like gravy. How it load balances across the NICs is not 100 percent perfect but it’s close and you can’t do that with Fibre Channel.”

It reduced von Stein’s sleepless nights and made network configuration trivial, especially when dealing with dynamic customer demands. And where change notices were fraught, now they are a formality; preparation reducing from hours to about half an hour.

And managing the new world of virtualisation has become less of a headache too.

“Virtualisation is becoming more used in all manner of business,” he says. “We’re now seeing larger clusters spanning large racks and areas of the data centre. You have islands that have an unknown interconnectivity requirement so how do you budget bandwidth when you don’t know which virtual machines are asking for connections?”

Fabric eases the reactive “pain” of capacity management: “We can’t get away from being reactive because customers don’t tell us what they’re doing, [but] being reactive in a fabric environment is a piece of cake. 

“If capacity is approaching, then all we do is run another link, activate and set as fabric; we literally just run another cable between two [devices], the switches find themselves and add that bandwidth”.

And von Stein points to virtual desktops as another factor straining the traditional client-server strategy. 

“Most organisations are online 24/7 so with the need to move applications and introduce new technologies into the data centre we don’t have the luxury of downtime.”

The macro trends driving the change swivel around virtualisation on the server and desktop and how end-users consume services through the cloud.

Easy access

“Everyone has a smartphone or iPad or remote access to applications in the data centre,” says Brocade A/NZ regional director Graham Schultz.

“[It’s] driving more users to centralised data [and] putting more stress on applications and infrastructure, driving the requirement for efficiencies in the data centre.”

According to surveys in the past year, Australia has the most virtualised data centres in the world, yet our businesses are decidedly diminutive by international SMB standards, Schultz says. 

“It’s not about how many employees you have but the type of business you’re running, such as cloud provision, that makes fabric worthwhile.”

And while fabric makes its way in the data centre, vendors such as HP see it moving down the value chain over the next 3 to 5 years into campus and branch offices. That’s according to HP’s solutions architecture manager, Wojtek Malewski.

“The sprawl of devices on campuses is impacting services and applications you are providing in the data centre so it’s important that fabric awareness and control not just be focused on the data centre itself,” he says.

And like vendors such as Cisco, HP hitches itself to the wagons of virtualisation vendors, most notably VMware.

“When talking about thousands of virtual servers, you’re talking about hundreds of thousands of lines of code,” Malewski notes.

“We see the death of the [command line interface]. A lot of vendors are stuck on [it] but to scale and move to cloud you have to abstract those requirements.”

He says many still do that heavy lifting by hand but what is needed is a single step to define [the] network and install services so sysadmins can rapidly provision that with a click.

“Don’t worry about policies or application programming interfaces; the network is provisioned on the fly as those services are looked at.”

Most see the move from 10GB Ethernet to 40GB Ethernet fabric in the data centre over the next 3 to 5 years as a given, with a similar order-of-magnitude rise in fibre channel fabrics in the same period to keep up with upward spiralling demand. 

Holistic approach

And while network behemoth Cisco has a big investment in the traditional three-tier architecture, it’s adapting to a holistic approach to the data centre, says its Australian chief technology officer Kevin Bloch. FabricPath is its foot in the door for this future, which consolidates switches so they are easier to manage.

“Say you have six switches in the data centre, FabricPath makes it look like they are one; it’s a huge simplification and prevents human error,” Bloch says. “And if you have another data centre, we can make them look like two switches.”

The question then is how to bridge the two data centres. 

“The solution to that is overlay transport virtualisation, which bridges those two fabrics over any network, even Layer-3,” Bloch proclaims.

“Where we’re going is to make those six switches to look like one fabric. Now we’re going over wide area, it could be dark fibre, and still simplify in a Layer-2 environment so you’re enjoying the benefits of Layer-2 with the flexibility of Layer-3.”

Nexus integration

Cisco’s Nexus switches are the first to benefit as Cisco parlays its market position to integrate with virtualisation leaders VMware and Microsoft, offering management benefits in the hypervisor. For instance, the Nexus 1000V demonstrated at Cisco’s conference in June supports Windows Server 2012.

Cisco hopes the conservativeness of data centre owners and its immense weight in the market gives it an edge even against aggressive competition. Bloch pushes Cisco’s total value proposition and reduced risk, the support it offers to partners and the surety the company boasts is infused with its brand.

And while he acknowledges that resellers not on Cisco’s top-tier do struggle against those that are, that’s an opportunity to differentiate with skills such as data centre automation or service catalogues.

Intel has also tooled around with fabrics for a few years but recently upped its game, buying QLogic’s Infiniband and the fabric division of legendary supercomputer maker, Cray.

Intel Australia enterprise technical specialist Peter Kerney sees Ethernet gathering the bulk of new business because that is where many technicians’ skills lie. But for high-performance architectures such as those used in big business, research and academia, Infiniband holds promise, he says.

“A lot of customers are looking at converged fabric storage over the Ethernet infrastructure to reduce switching gear and connections, which also collapses storage and network teams at customers and ultimately resellers as well,” Kerney.

* Nathan Cochrane attended Cisco Live! as a guest of the vendor.