What does this mean to you? If you're a non-Mac shop, Parallels server will be yet another hypervisor-based solution for virtualizing server and client OSes, complementing SWsoft's Virtuozzo Containers Server virtualization offering. Existing Virtuozzo customers can use the Virtuozzo management interface to control both platforms. Parallels Server runs 32- and 64-bit flavors of Windows and Linux on Intel-based hardware, with full support for VT-x and experimental support for second-generation Intel VT-d chipsets (Intel Virt technology for Directed I/O). You won't be able to run Apple guests on non-Apple hardware, but then if you're a non-Mac shop you probably don't care about Mac OS.
If you're administering a Mac shop, Parallels server is currently the only game in town for hosting multiple instances of Leopard Server (Mac OS 10.5) alongside Win2K3, Win2K8, Solaris, Linux distos, etc., on Apple hardware. The product runs on any Intel-based Mac all the way up to the just-announced Harpertown 8-core Xserves. This is the first solution for running multiple instances of Mac OS on the Intel platform; Apple licensing permits Leopard Server to run as a guested OS. Development houses and production environments can finally have easily managed Mac OS sandboxes with all the conveniences of other VM platforms such as snapshots, rollback, and migration.
To be crystal clear, running Leopard Server on non-Apple HW is not permitted by the EULA, nor are Apple client OSes currently covered under the new-for-Apple "relaxed" virtualization guidelines. It will be interesting if any changes to the client boilerplate surface after next week's keynote or whether Apple will care one way or another about end users guesting Leopard clients.
My experience with the beta so far: the pre-pre-release version I've been working with doesn't do a great job with fresh installs. I've been running an OS 10.5 server guest image provided by SWsoft for testing. I have not had success building a new image from scratch, nor attempting to NetBoot a home-grown server image. I have run a range of functional tests and applications on the guest OS without any issues. I have suspended an OS instance, migrated from one physical box to another and restarted with no issue. I have simultaneously run a Leopard guest and a Red Hat DNS server on an Xserve, each with one virtual CPU. I like what I've seen, early warts and all.
Parallel's claims for final production code include up to 4-way SMP per guest, a max 64 Gbytes of host RAM, and support for more than 50 x86 and x64 operating systems. If the stars align this spring, I will be testing the full release version in our virtualization lab to see how functionality and performance stack up against other hypervisor-based platforms.
