With Windows Server 2008 Hyper-V and the upcoming release of R2, Microsoft is driving full speed ahead towards server virtualization. Their efforts are not only limited to Hyper-V, either. In fact, Microsoft has begun to produce applications — server applications, specifically — that are designed to be virtualized.
These virtualization offerings are now fully supported either on Windows Server 2008 Hyper-V, Windows Hyper-V Server or any other hardware virtualization platform that has undergone certification through the Server Virtualization Validation Program (SVVP). Currently, certified vendors for SVVP include VMware, Citrix, Novell and Cisco, though VMware was the first to achieve this level of certification.
With this move towards virtualization support, more and more Microsoft server products will be designed specifically with virtualization of the workload in mind. This is the case for SQL Server 2008, among others. When you run SQL Server 2008 on Windows Server 2008 inside a virtual machine (VM), you stand to gain several advantages:
- First and foremost, you can consolidate your existing and future databases. Depending on its configuration, each SQL Server virtual machine can run any number of databases.
- You can also support further consolidation by creating multiple SQL Server instances inside each virtual machine.
- While older versions of SQL Server can be virtualized, they are not optimized for virtualization. With SQL Server 2008, Microsoft has enhanced the code to take advantage of virtualization through tight integration with virtual system drivers.
- You should run SQL Server 2008 on Windows Server 2008 to obtain the very best performance in virtual machines. As stated earlier, Windows Server 2008 is designed as a virtualization-aware operating system from the ground up. Older operating systems such as Windows Server 2003 and even Windows 2000 Server have also been optimized for virtualization, but this has been done through the application of service packs, not the design of the code from the ground up.
What is the Hyper-V VMBus?
Hyper-V includes a minimal microkernel architecture which allows multiple partitions to access the same physical hardware resources. Keeping the hypervisor small helps decrease the security attack surface and keeps things efficient. Child partitions require the ability to communicate with the parent partition for management purposes.
This is done through the use of a logical point-to-point VMBus. Worker processes service administrative operations and requests -- such as starting or monitoring a VM -- from each of the child partitions. The VMBus uses shared memory to securely communicate with VMs on the same host server.
-- Anil Desai, Microsoft MVP
- Running SQL Server 2008 on Windows Server 2008 will let SQL Server take full advantage of the synthetic drivers included in the operating system. When you run both on top of Hyper-V, the virtual machine will be able to run as an enlightened guest and directly access virtualized hardware through Hyper-V's VMBus, taking full advantage of the Hyper-V platform.
The advantages of virtualization are undeniable. Each hard disk drive for the VMs is contained within a virtual hard drive — drives that are contained in files on the physical disk — which makes them very easy to back up, duplicate or replicate. In addition, running SQL Server within virtual machines supports complete and absolute isolation among all database instances, yet lets you take full advantage of powerful new x64 hardware by running several virtual machines. Better yet, running SQL Server on hardware virtualization engines such as Hyper-V is now fully supported.
Server virtualization is here to stay and even demanding workloads such as SQL Server 2008 can take advantage of this new operational model with little or no performance loss. If you are deploying SQL Server 2008, you should seriously consider this model as a perfect way to consolidate your databases.
Next up: Creating fault-tolerance virtual installations
ABOUT THE AUTHORS
Danielle Ruest and Nelson Ruest are technology futurists focused on datacenter optimization and continuous service availability. They are authors of multiple books, notably "Training Kit 70-652: Configuring Windows Server Virtualization with Hyper-V" published by Microsoft Press and "Virtualization, A Beginner's Guide" published by McGraw-Hill Osborne. For more tips, write to them at firstname.lastname@example.org.