Underexposed

If market-leading VMware, open-source incumbent Xen, and Microsoft's upcoming Hyper-V aren't enough choices, another one is on the way: Parallels Server.

SWsoft, which is in the process of renaming itself Parallels, released its first beta version of the server virtualization software Wednesday. SWsoft itself has chiefly focused on commercializing higher-level virtualization software called Virtuozzo that lets a single version of an operating system be subdivided into semi-independent containers. However, the company's Parallels division has come to prominence by letting a single computer--most notably an Intel-based Apple machine--run Windows.

That Parallels technology is now available as a hypervisor that runs on a computer's "bare metal," a contrast to the previous technology that runs on top of a host operating system such as Mac OS X. The hypervisor approach, also employed by VMware's ESX Server, Xen, and Hyper-V, is generally preferred for servers to the guest-host model.

Parallels Server's claim to fame over its rivals is its ability to run multiple versions of Mac OS X, and it's "the first to run multiple copies of Mac OS X Server on a single Apple computer," the company said. The server beta also is the first hypervisor to support Intel's second-generation VT-d virtualization hardware, though it's still at the experimental level, the company said.

Those are interesting accomplishments, but they don't seem to me to be the competitive breakthroughs that will dent VMware's prevailing dominance. Apple's Xserve machines account for only a tiny slice of that market compared with those running Windows and Linux, and support for the latest Intel hardware doubtless will spread to rival hypervisors.

So it's probably a good thing for SWsoft/Parallels that it also has its Parallels desktop, Virtuozzo, and virtualization management software lines up and running. Parallels Server could well appeal to the sizable number of customers who already have Virtuozzo and accompanying management tools installed. Those folks might want to expand into new virtualization territory. To take one niche where Virtuozzo found early success, Web site hosting companies could offer more independent partitions to customers who are sharing a server.

Those who wish to test the Parallels Server beta software can apply at SWsoft's Web site.

VMware announced details of its forthcoming Virtual Infrastructure 3.5 on Monday, including an experimental feature to shut down servers if they're not necessary.

The feature, called Distributed Power Management, monitors how hard servers are working and moves virtual machines to new machines to let unneeded servers be shut down. When workload picks up again, the servers are powered up again, according to the publicly traded EMC subsidiary.

Virtual Infrastructure includes two main components. First is ESX Server, the underlying hypervisor that lets a single physical computer run multiple operating systems simultaneously in compartments called virtual machines. Second is VirtualCenter, which lets administrators monitor and manage those virtual machines.

Among other new features in VI 3.5, which is scheduled to be generally available later this year:

• The new ESX Server 3.5 gives Linux a boost with support for paravirtualization, which speeds some operations when the operating system is tailored to run on a virtual-machine foundation. It also can use a hardware feature called nested page tables that speeds memory accesses, modernizes storage and network abilities, and can run on servers with up to 128GB of memory.

• VMware Update Manager, which allows administrators to monitor which patches have been applied to operating systems and to apply those patches, regardless of whether a virtual machine is running or paused and saved to disk.

• Storage VMotion, a feature demonstrated at VMworld that lets a database's data store be moved from one storage system to another even as it's in use. The feature can be handy when taking a storage system down for repairs or upgrades, though the network resources required to move the data store to a new storage system can consume some of the capacity the database had when running ordinarily.

VMware sells VI in three editions: the basic Foundation, the mid-range Standard and the top-end Enterprise. For every two processors installed in a server (a processor being an x86 chip with up to four cores), Foundation costs $995, Standard costs $2,995 and Enterprise costs $5,750.

The Foundation product used to be called Starter, but the renamed version now removes previous limits on server processor count, memory utilization and shared storage.