In our latest set of test of virtual machine management tools, we examined VM host-centric management, planning and accounting applications from PlateSpin and Virtugo Software, a VMware plug-in for Microsoft's Operations Manager application from nWorks, and a storage-area network management tool from Onaro (which Network Appliance has just acquired) that offers specialized insights into the virtualized world.

We also tested the management wares that come as part Parallels (formerly SWSoft) Virtuozzo virtual application platform. And we assessed the usefulness of Reflex Technologies' VM IPS.

In previous tests, we analyzed the management capabilities offered by the major VM vendors, and reviewed third party management tools that have specialized conversion capabilities and VM instance building.

The tool that offers the broadest range of management features is the open source Hyperic HQ toolset.

We've identified six key areas that need to be addressed in order to make VM management a workable venture in a large deployment:

• How are VM snapshots versions tracked?

• How are moves, adds and changes of VM hosts, their guests, the kind of applications used on them administered?

• How is VM and application availability monitored?

• How are user and administrative roles managed across VMs?

• What forensics mechanisms are available to help determine why a VM was drastically altered in any way?

Each of the products tested hits our list of ideals in some fashion, but none nail all of them. PlateSpin's PowerRecon and Virtugo's virtualSuite provide availability monitoring, moves-adds-changes tracking, and operational-history tracking for forensics, as does nWorks for VMware. Onaro SANscreen VMInsight has very appealing SAN monitoring and planning capabilities that add much needed SAN management, monitoring, and control for VMware's VirtualCenter and SAN-connected VM guests residing within a VMware hardware host.

Each has limitations, though, either in terms of the platforms they support, the actions they can take without adding optional software, the level of image auditing and forensics they provide and in the hierarchy of user and administrative roles they support.

What we've learned from testing almost 20 products is that there is no silver bullet. There is no single tool that will hit on all six virtual management ideals we've outlined. And like in the early days of network management and the client management markets, administrators will be forced to cobble together multiple tools to get the job done until the industry has a shakedown that forces necessary mergers, partnerships and acquisitions.

Henderson and Dvorak are researchers with ExtremeLabs in Indianapolis. They can be reached at thenderson@extremelabs.com