Finally emerging from beta after Microsoft told an already anxious customer base in May of last year it would eventually be available early in first quarter 2007, Service Pack 1 of Virtual Server 2005 R2 has at last emerged from beta. But some customers looking for a feature that Microsoft brochures said it has may be disappointed today to learn they really should have said it's a feature that SP1 supports (big difference): Volume Shadow Services.

For users of Windows Server 2003 on physical systems, the support is actually good news. They already have VSS, which currently enables them to take backup "snapshots" of their hard drives while they're running, for possible restoration to an earlier state in case of an emergency. After SP1 is installed, their existing VSS software will take similar snapshots of virtual hard drives as well as physical ones.

But Microsoft marketing literature explained the VSS support as a feature the new SP1 would include, as though there were a new switch or menu command in the administrator Web site allowing VSS.

As beta testers were already aware, there's no such command or switch - we looked for it ourselves just to make sure - so if you're running SP1 from XP or Vista, there's no big bonus for you.

That news was posted this morning on the blog of Microsoft's general manager for virtualization strategy, Mike Neil: "A new feature to the service pack is Volume Shadow Services, which provides improved support for backup and disaster recovery." That statement was in turn passed on by other sources.

In another marketing e-mail today, Microsoft carefully tells a more accurate story. It notifies SP1 downloaders that "customers will now be able to take snapshot backups of physical machines, with no downtime, that will in turn take snapshots of all the virtual machines on that physical host."

Indeed, that's how the new VSS support works, but only for users who already have VSS backup software: That software will now be able to take a backup snapshot whose contents are restricted to the .VHD file, and that file will essentially serve as a VSS snapshot, even if the guest operating system (the one being virtualized) doesn't have VSS support.

Among the list of foreign guest operating systems Virtual Server now supports, you can add Novell SUSE Linux Enterprise Server 10 and Solaris 10. Microsoft's literature this morning states this brings to 11 the number of non-Windows operating systems currently supported. However, an earlier presentation some months back had already listed 16 systems supported by Microsoft Operations Manager's snap-in management packs for remote virtual machines, so we'll need to verify that fact as well.

Last April, Mike Neil indicated that SP1 could have been delayed until as late as July.