VMware offers virtual machine (VM) technology for the server arena with ESX and GSX Server. Both products let you run multiple, simultaneous server OS sessions on a single system--a definite advantage for companies wanting to trim the fat from the data center.
Connectix--best known for Virtual PC, an emulation product for Windows and Macintosh desktops--recently announced Virtual Server, an enterprise-class server virtualization based on Virtual PC's emulation technology.
According to David Atlas, Connectix VP of marketing, Connectix has pumped up the functionality of its virtual machine technology for enterprise use. Virtual Server features a virtual network architecture that supports up to four NICs per VM, virtual switches, and remote management capabilities, and will run on any IA-32 server architecture, from blades to 16-way servers.
Initially targeted at enterprises in the financial, insurance, healthcare, government, and manufacturing industries--companies typically plagued by high IT spending, distributed resources, and legacy systems--Virtual Server is positioned to compete directly with VMware's ESX server in terms of features. ESX Server is a ground-up solution that supplies its own platform for running virtual server machines. For enterprises with entrenched fleets of Windows-based servers, ripping out an existing server platform for the sake of consolidation is a daunting prospect. Virtual Server, by contrast, runs on top of Windows like its progenitor, Virtual PC. Says Atlas, "Virtual Server can run on all your Windows machines--not only the new whizbang 8-way you are purchasing from your big server OEM, but also all the other machines (1-ways and so on) you already have installed."
The convenience of this approach sounds almost too good to be true. An inevitable tradeoff would seem to be a sacrifice in performance due to the overhead of running Windows itself--as opposed to a dedicated, barebones platform like ESX. But Connectix is convinced there are no tradeoffs with Virtual Server--in fact, Atlas says initial tests suggest that Virtual Server offers performance equivalent or superior to that of ESX Server. Of course, it's too early to verify this, since Virtual Server is still in its initial partner- and customer-testing phase. "This is very preliminary," says Atlas, "and customers are advised to run their own benchmarks."
But Atlas says running on the Windows platform offers other benefits. "Third-party hardware peripheral and software support, for example, is much greater when you support the Windows device model." The product's design is also quite extensible, letting you build applications on it using any COM-supported language--Java, Perl, C++, C Sharp, for example--which should please companies that do a lot of in-house development.
Another cited advantage over ESX Server is broader OS compatibility. Thanks to the product's faithful IA-32 emulation, it supports a wide variety of guest OSes, including NetWare and OS/2 (in addition to Microsoft's various server OSes).