High-availability Exchange made easy

The obvious solution for bringing HA (high availability) to your Exchange server is to use Microsoft’s own Exchange clustering features. Although Exchange’s clustering is reliable and robust, this isn’t an easy configuration to set up. It’s also usually costly, not only in terms of additional hardware and software licenses, but also because it requires a skilled Exchange administrator.

In a large enterprise environment, it’s likely that one or more senior Exchange admins are already on staff, so this approach makes excellent sense for customers of this size. Small businesses with 25 users or less, however, will probably get better bang for their buck by choosing an Exchange hosting service. And midsize companies that need real high-availability but don't have dedicated Exchange administrators on staff might be better served by a mixed approach, recently referred to as “mid-sourcing.”

The Azaleos and Teneros solutions reviewed here fall into the latter category. Both are complete Exchange HA solutions that are installed on the customer’s premises, but managed and monitored off-site. The Teneros product is well-suited to midsize businesses approaching 250 users, whereas the Azaleos product is built to support thousands.

We began the test by building an Exchange 2003 server to act as our existing TestCustomer server. This ran on a Dell PowerEdge 1800 with dual 3.0GHz Intel Xeon CPUs and 1GB of RAM with Windows Server 2003 installed. We also attached a client workstation running Outlook and using Internet Explorer to connect to Outlook Web Access. Our test products had to install in and around this infrastructure, with points awarded for easy installation and a minimum of user interruption.

AzaleosOneServer

Boil the Azaleos OneServer down to its essence and you’ll find a full-featured Microsoft Exchange Server 2003 cluster slickly prepackaged into a ready-made solution, although not exactly an appliance. The company shipped us a configuration consisting of three Dell PowerEdge 1850 servers and a Dell PowerConnect 5324 switch ready to be installed. The customer is responsible for providing a network storage appliance (usually obtained through an Azaleos partner) as well as an Active Directory domain controller. For our test, Azaleos loaned us a NetApp FAS270 filer to serve as the SAN resource.

If the OneServer deserves the appliance name, the reason is the Azaleos front-end for e-mail administrators to manage the device. The functionality is all Microsoft Exchange clustering, but the Azaleos interface is much easier to use. The initial configuration is shipped with the system on a USB key, based on information provided by the customer, including an IP address range for the servers and an Active Directory domain name. To keep this simple, Azaleos provided a questionnaire prior to delivery with an easy-to-follow matrix.

If there is an existing Exchange environment, mailboxes and public folders can be migrated to the Azaleos appliance for high availability. Less critical mailboxes or public folders can be left on the existing, nonclustered server, or that server can be removed entirely. According to Azaleos, the setup can be performed by the customer with an installation script or by an Azaleos engineer on-site depending on customer preference.