Virtual network appliances cannot match the performance capabilities of dedicated hardware, and virtual wide area network (WAN) optimization appliances have been no exception. WAN managers have used virtual WAN optimization appliances for lightweight tasks in branch offices, such as accelerating HTTP traffic or business applications. Now vendors claim that a new generation of virtual WAN optimization appliances can handle the heavy-lifting -- data center to data center optimization for data replication and disaster recovery (DR).
Regardless of vendor claims, enterprise adoption of high-performance virtual WAN optimization appliances for data replication and DR will partly be a cultural decision, said Joe Skorupa, research vice president at Gartner Inc. The culture in most enterprise IT departments will view anything besides dedicated hardware with heavy skepticism, he said.
If it proves to handle the load, I don't have any reason not to use it.
Mahmoud Harb, Site Operations Manager
"Those folks are the most conservative and the implication of failure is the greatest," Skorupa said. "You're playing high stakes poker there. These people want the best possible performance, the greatest possible reliability and the least likely scenario where someone is going to goof and misconfigure the virtual appliance. They are very, very risk-averse. They're belts and suspenders people."
Silver Peak, which markets itself as a data center-class WAN optimization vendor, recently announced the VRX-8, a virtual WAN optimization appliance. The product can operate at up to 1 Gbps, provided it sits on a server with at least eight central processing units (CPUs), according to Larry Cormier, senior vice president of marketing at Silver Peak.
Other vendors' virtual WAN optimization appliances top out at 250 Mbps (Expand Networks), 45 Mbps (Riverbed Technology) and 18 Mbps (Blue Coat Systems). Skorupa expects them to follow Silver Peak's footsteps. At least one vendor, which he declined to name, will likely release a 3-5 Gbps virtual WAN optimization within the first half of 2011, he said.
High throughput not only requirement for data replication
High throughput alone isn't going to sanction a virtual WAN optimization appliance as DR-ready, Skorupa said. Networking pros will also consider the variety protocols that a virtual appliance must support, as well as whether they have the manpower and hardware on hand to support it.
WAN managers going the virtual route must be mindful of their hardware choices and also consider what other server tenants would shack up with high-performance virtual WAN optimization appliances being used for data replication and DR, according to Andre Kindness, senior analyst at Forrester Research.
Putting a gigabit virtual appliance on a server that doesn't have much excess compute power may turn it into a de facto dedicated appliance, negating the benefits of virtualization, Kindness said.
"When you do backups, really you do it when people aren't using the network. I think the issue is going to be where people throw on [virtual] firewalls … [which are] going to be running all the time," he said. "Any other application is going to become second in line [to WAN optimization]."
Networking pros not ruling out virtual WAN optimization for DR
Some networking pros who have already adopted WAN optimization and server virtualization said they wouldn't distrust virtual WAN optimization for data replication and DR on principle. But they would have to see it to believe it.
"In general, I would trust vendors to deliver [on their claims], but [our adoption] would depend very much on the size and changeability of my own data sets, setup of network and data centers, size and reliability of network connections, et cetera," said Ernest Ostro, director of information services at global nonprofit Pathfinder International, which uses Certeon's aCelera Virtual Appliance at branches throughout Africa, Asia and the Middle East.
"There are some really interesting network optimization technologies out there," Ostro added. "[But] like all new technologies, I would need to do due diligence."
Mahmoud Harb, site operations manager at CareerBuilder.com, a large job postings website, uses Silver Peak's high end NX-8000 series physical appliance to optimize two terabytes of database replication traffic daily between his primary data center in Atlanta and his DR site in Chicago.
As a self-proclaimed cloud and virtualization devotee who has had success with Silver Peak's lower-end VX series virtual appliances for regional offices, Harb said he would have to test a data center-class virtual WAN optimization appliance before he considered replacing his NX-8000 appliances with them.
"If it proves to handle the load, I don't have any reason not to use it," Harb said. "Until I have my hands on it and test it in production, I don't know the complete answer. But my experience with Silver Peak and their products so far is that once it becomes available, I'll feel comfortable [trying it]."
Let us know what you think about the story; email: Jessica Scarpati, News Writer.