Performance & Remote Access of Virtualized Applications

Virtualization Meets Remote Access

Enterprises have come full circle. In the 1990s, data center computing gave way to distributed computing. Distributed computing has now given way to consolidating resources back to the data center via virtualization. However, as computing resources have become more centralized, users have become increasingly more distributed. The large population of corporate-centric users that fed the growth of the local area network (LAN) is greatly diminished; now, more than 75% of today's workforce work remotely and access centralized corporate resources over the wide area network (WAN).

Today's remote/branch office environments share a common set of issues, including:

• Lack of on-site IT administration

• Five to 10 workloads for file, print, email, NAC, directory, Web, applications and VPNs, but no space for servers

• Shrinking budgets to power and cool servers

• Unreliable availability and backup resources

Many enterprises are deploying centralized virtualization, where remote offices access virtual machines (VM) on a centralized server in the data center. This approach provides IT managers with the maximum server consolidation ratio, cost savings, and use of management and support resources. However, this approach does not take into account the impact that the WAN can have on remote office productivity. In a survey conducted by the Aberdeen Group of more than 170 organizations regarding their best practices for optimizing remote delivery of business-critical data, more than 77% of the respondents said they were concerned about the impact of server and desktop virtualization on the performance of their mission-critical applications.

This juxtaposition of centralized computing resources with the remote users who need to access those resources puts a tremendous amount of stress on existing WAN technologies. Latency, network contention and packet loss negatively impact WAN response time and, ultimately, remote user productivity. As more and more IT managers embrace virtualization to meet important cost-reduction and cost-management initiatives, they are running head-on into the limitations that the WAN imposes when branch office users remotely access virtualized applications from a centralized data center.

Two Approaches to the Same Problem

IT managers have a number of different approaches to consider that can address these remote application access performance issues. These approaches merge virtualization, network optimization, and application acceleration within data centers and remote offices. Two approaches attack the problem from two different angles - one adds a virtual machine partition to a physical acceleration appliance; the other incorporates a virtual application acceleration capability directly into the virtual machine infrastructure.

Adding Virtualization to WAN Optimization Appliances

WAN optimization solutions that are based on proprietary operating systems and hardware (i.e., physical appliances) residing at the data center and in remote offices are typically "closed" boxes that cannot accept other applications running on the appliance. Some manufacturers of these solutions have "opened" these boxes just enough to allow a VM partition to run on the appliance along with a limited number of applications. This enables vendors to maintain a hardware footprint in their customers' data centers and branch offices, as well as limited participation in a vendor-defined virtualized infrastructure. The benefit to customers is that they can capitalize on their investments in these proprietary hardware appliances, as well as add some features of a cost-effective virtualized environment.