Virtual servers can benefit an organization’s data crunching needs in many ways. One of them is leveraging their native benefits to broaden the availability and recovery options for Microsoft Exchange 2010 deployments.

Most administrators can cite the benefits of virtual machines by rote:

* They’re portable so Exchange need no longer be bound to a particular piece of hardware. That means design decisions don’t need to be permanent. CPU and memory requirements can be changed with a reconfiguration and reboot. What’s more, new hardware can be be more easily accommodated because the virtual machine containing Exchange can be simply transferred to the new machine.

* They’re hardware independent so planners have greater design flexibility putting together the production as well as the disaster recovery components of a system.

Some virtual machine vendors, like VMware, have included robust availability features into their software. For example, the company’s High Availability product can act as a first line of defense against server failure. If a physical server or any critical component in a server goes down or fails, HA will automatically reboot the Exchange virtual machine on another physical server.

Another VMware product, Distributed Resource Scheduler, is designed to automatically manage workloads for virtual machines on a network. Better management of demand on a network means less latency and happier users. For example, if a virtual machine becomes bottlenecked, DRS can automatically move it to another host with more resources. Better yet, it can do that without subjecting the system to downtime.

The product can also speed recovery from hardware failures. For instance, after HA addresses a breakdown in a physical server by moving an Exchange virtual machine to another physical server, it’s DRS that migrates the Exchange VM back to its original home after it’s fixed, once again without downtime or any hiccups to the system’s users.

Running Exchange in a virtual environment can increase the availability of the program across its lifecycle. Virtualized Exchange can easily recover from planned or unplanned hardware outages, from hardware degradation by better load management and from application failure by using Microsoft Cluster Service   within a virtual machine.

In addition, the architecture of virtual machines has multi-pathing capabilities and advanced queueing techniques that can be leveraged in a virtual Exchange environment to improve network performance. For instance, they can be used to increase IOPS transactions, which will allow more clients to be served. Those technologies can also be used to balance the workloads of multiple Exchange servers that are sharing the same physical server to use multiple SAN paths and storage processor ports.

An added bonus to locating Exchange on a Virtual Machine File Server is avoidance of SAN errors. That’s because the VMFS hides SAN errors from guest operating systems.

Upgrades can be a bear in Exchange environments. Not only are they complicated to perform, but they can produce downtime which doesn’t produce happy faces in an organization.

A typical upgrade involves allocating engineering resources–including application, server and SAN administration–for planning and implementation, sizing and acquisition of new hardware and, of course, the downtime to perform the upgrade.

Compare that to an upgrade in a virtual environment. Scaling up your Exchange environment, for instance, is as easy as adding more Exchange virtual machines as your client base grows.

When Exchange is running on a physical server it’s tightly bound to a storage technology and can be very challenging to scale. Adding more storage to an Exchange virtual machine, however, can be easier. VMware’s vSphere software, for example, treats the new storage as a simple SCSI device. That means regardless of the storage technology–SCSI or Fibre Channel–the Exchange environment can be upgraded without a sneeze.

Changing the storage capacity for Exchange when it’s running on a physical server can be difficult, too. Not so in the virtual environment. With VMware’s Virtual Machine File System, for instance, storage capacities to Exchange virtual machines can be changed on the fly with its hot add/remove storage feature.

As VMware notes in a recent white paper on availability and recovery options when running Exchange 2010 in a virtual environment: “Although application-level clustering has been the prevalent solution for most Exchange implementations, features of the vSphere platform can enhance the overall availability of Exchange by providing options
that help to limit both planned and unplanned downtime.”

“In fact,” the company added, “for many organizations, the features provided by vSphere may satisfy the availability requirements of their business without needing to follow traditional clustering approaches.”

As for organizations with high availability requirements, VMware notes, “application-level clustering can be combined with the vSphere features to create an extremely flexible environment, with options for failover and recovery at both the hardware and application levels.”