VM WARE or WAR!

Written By: Steve Kaplan - INX

Microsoft extends most of its virtualization licensing benefits to platforms other than just its own Virtual Server. An organization, for instance, can run up to four instances of Windows Server 2003 Enterprise Edition on a VMware ESX Server by purchasing just one license. Microsoft’s stance in regards to virtual appliances, though, remains unclear. On one hand, the company amended its licensing agreement this year to no longer require Virtual Server in order to activate a published Microsoft Virtual Hard Drive (VHD)-formatted virtual machine. On the other hand, Microsoft anti-virus and activation mechanisms cause these virtual machines to de-activate when they are run on other virtualization platforms. As virtual appliances continue to proliferate, this confusion may negatively affect the ultimate popularity of the VHD format.

The Allure of Virtual Appliances

Virtual appliances are quietly revolutionizing the distribution of both software and specific application functionality. Hardware appliances manufactured by Cisco, Citrix, Checkpoint and many other firms have long been sold to handle isolated IT functions such as VPN, back-up and firewall. This method of application distribution has several advantages over simply distributing software applications to be installed by customers on standard X86 machines. The hardware appliance typically includes a slimmed down version of the OS tailored to optimally manage just the specific application. This utilizes the computing resources more efficiently while improving reliability, simplifying troubleshooting and enhancing security. It requires less frequent patching and eliminates problems resulting from customers using incompatible hardware or from incorrectly installing the application.

The downside to hardware appliances is that they are costly to purchase. They take up rack space and require power to both operate and to cool. Hardware appliances result in more underutilized servers and in non-standardized hardware in the datacenter. They have parts that can fail meaning that duplicate devices may be required in order to guarantee redundancy. Further redundant devices may be required at disaster recovery sites.

By repackaging a hardware appliance as a virtual appliance, manufacturers gain all the advantages of utilizing a specialized operating system in a controlled environment, but without requiring a dedicated hardware server. Deployment is simplified, costs are reduced and high availability is enabled without requiring duplicate hardware. The virtual appliance can even be replicated off site for disaster recovery. Downloading, deploying, evaluating, and replacing virtual appliances is also much quicker and easier.

Software manufacturers are increasingly delivering their applications as virtual appliances for these exact same reasons. By packaging, say, a database as a virtual appliance, the software manufacturer no longer needs to be concerned about what hardware, drivers and OS version the application is being installed upon. The manufacturer’s best practices are already incorporated into the virtual machine ensuring that it is configured correctly. Complexity is reduced while reliability is improved. Manufacturers currently selling virtual appliances range from well-known industry leaders such as BEA to hundreds of small firms who are capitalizing on the enhanced functionality that virtual servers enable in terms of performance, reliability and security.

Virtual appliances enable further advantages when operating within a largely virtualized infrastructure. Organizations can collapse more of the infrastructure services into the virtual infrastructure along with the application servers. Virtual appliances relying on the network transport, such as firewalls, gain significant performance advantages by keeping the connections inside of the physical host servers utilizing the virtual switch. There is less latency within the virtual infrastructure than routing traffic from the virtual infrastructure out to the physical network and back.

Virtual Appliance Format

VMware currently dominates the virtual appliance market with its Virtual Machine Disk Format (VMDK). Microsoft is taking a big gamble by not fully supporting the running of its VHD format virtual machines within a VMware environment. VMware is the world’s fastest growing large software company in history – by a factor of two. The company will do well over $1 Billion in sales this year and shows no sign of slowing in terms of revenues, innovation and leadership. Over 10,000 attendees are expected at this year’s VMworld in San Francisco, and VMware centric organizations tend to be exceptionally enthusiastic about the platform.

Should Microsoft continue its restrictive stance on virtual appliances, it may compel some organizations to choose its virtualization platform over VMware. But it will also, without a doubt, push many software manufacturers to go through the trouble and expense of rewriting their applications to utilize an open systems based operating system as part of a virtual appliance. Alteratively, by promoting Windows based virtual machines within all formats, Microsoft has an opportunity to evolve the traditional operating system– designed to support many disparate applications – to the new slim, high performing and secure O/S component of virtual appliances.