How to Use Virtualization to Accelerate Remote Backup and WAN Replication

By Shawn Cooney  |  Posted 2009-11-17

How to Use Virtualization to Accelerate Remote Backup and WAN Replication

The remote backup and recovery end game is simple. You should be able to perform frequent backups with shorter backup windows to protect as much company information as possible. You should be able to do this regardless of the miles between your source and target replication locations. But before I get ahead of myself and dig too deeply into the technology, let's get some facts on the table.

The volume of data that must be protected by solutions such as replication and backup continues to grow by leaps and bounds. The cost of storage to IT is growing at a rate approaching 60 percent per year. The more data you store and need to protect, the more network bandwidth you will be required to purchase for replicating or backing up that data between sites. It seems like a simple equation.

Bandwidth has a direct impact on your ability to improve data recovery capabilities and limit loss. However, buying more network bandwidth for your WAN may not be the best investment to achieve your goals. Latency, congestion and packet loss can annihilate the throughput of any WAN. Latency is caused by limits in the speed of light over distance and it can reduce effective bandwidth by 90 percent. Bigger links are impacted more by the effects of latency.

To add insult to injury, networking protocols reduce link speed by half every time a packet is lost due to congestion or errors. Ramping back up to maximum speed can take time. If a second data packet gets lost, then the link speed is cut even further. And packets do get lost. Loss rates on most WAN links average around 0.1 percent, which can cripple effective throughput. As network distances approach 500 miles, a T-3 line will only provide around 40 percent effective bandwidth if no efforts are made to work around this problem.

According to a recent survey on WAN disaster recovery capabilities, nearly half of North American and European enterprises reported that network bandwidth costs represent between 20 percent and 80 percent of the total cost of data replication-and these are recurring monthly costs. Improving recovery time without increasing bandwidth is important. So, how do you break this costly dependency on network bandwidth to support increased volumes of replicated data-and do this while meeting your backup and recovery time and point objectives?

WAN Optimization Minimizes Bandwidth Dependency

WAN optimization minimizes bandwidth dependency

WAN optimization minimizes the dependency on more bandwidth. WAN optimization technologies have brought down the bandwidth side of the cost equation for data recovery. They have made it possible for small and midsize businesses to consider, if not implement, data replication.

Realistically priced WAN optimization technologies have also encouraged larger enterprises to extend replication to remote offices as a result of reducing bandwidth utilization and costs.

WAN optimization virtual appliances take data recovery to the next level. Just as virtualization technologies have been a boon to server consolidation and application availability, software-based WAN optimization virtual appliances are a boon to any company looking to protect its corporate data. WAN optimization virtual appliances provide the same or greater increases in effective WAN bandwidth and throughput, for much less cost.

A virtual appliance runs on top of industry-standard servers, supporting virtual machine hypervisors such as VMware ESX and Microsoft Windows Server 2008 Hyper-V. Much like a hardware WAN optimization appliance, virtual appliances are deployed in the data center and at each branch location. They work together to intercept and accelerate data moving back and forth.

The primary differences between the virtual and physical WAN optimization appliances are cost and flexibility. Hardware appliances are typically expensive and come with strict, closed configurations not associated with software. This means the appliance vendor controls hardware upgrades, which could lag x86 server advances and scaling capabilities. This results in expensive, user-disruptive forklift upgrades. Acquisition and total operational costs of hardware WAN optimization appliances can be as much or more than the total costs of servers and maintenance at the branch office.

Software-based WAN Optimization Virtual Appliances

Software-based WAN optimization virtual appliances

Software-based WAN optimization virtual appliances work within a VM and completely leverage the virtualization environment for easy provisioning, management, high availability and resource allocation. Virtual appliances use system resources (CPU, memory, storage) that can be upgraded as required based on policy prioritization. Software virtual appliances can be dynamically scaled and moved around, enabling you to allocate the WAN optimization function where it is most needed.

WAN optimization virtual appliances provide up to 95 percent greater throughput between data centers and/or replication branch offices. Backup and replication applications can experience up to ten times the performance. The resulting effective network bandwidth exceeds the rated bandwidth depending on the effect of the compression algorithms. In many cases, bandwidth optimization will exceed 95 percent.

Virtualization technologies are now mature, flexible and scalable enough to provide high- performance data recovery services to smaller, less mission-critical locations and users through more cost-effective WAN optimization virtual appliances. In most cases, WAN optimization virtual appliances can save 60 percent in equipment and bandwidth costs versus hardware appliances.

In addition, if you contract for data backup and recovery services, you should evaluate WAN optimization virtual appliance software before you sign on the dotted line for tape-based recovery and replication. Data backup and recovery services may seem affordable, but you could lose out big if they do not meet your recovery time and point requirements-whether you are a small or large company.


If you need a data recovery solution for your distributed enterprise, or a faster or more cost-effective one, then you need to evaluate WAN optimization virtual appliance software. It will maximize your investment in your WAN infrastructure and your backup-and-recovery application environment. WAN optimization virtual appliance software can deliver the results that you need to cost-effectively protect and maintain your company's most valuable asset: its data.

Shawn Cooney is Director of Research at Certeon. Shawn has more than 25 years of experience in information and network security. He has expertise in digital rights management, MPEG compression and networking security. Shawn holds a patent in audio and video compression over IP networks. He was also a member of the IETF MPEG 4 Systems and Digital Rights Management committees. Prior to Certeon, Shawn founded software copyright protection and digital media companies, and was a senior consulting engineer at EMC. He can be reached at

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