Microsoft’s move to add its Hyper-V driver software into the Linux kernel is not a sinister ploy to sink open source software. Rather it’s a sign of how vitally important virtualization is to the server software market place. Few customers would take Hyper-V seriously until it runs Linux software as well as competing hypervisors.
Without this kind of driver integration Hyper-V could never hope to do a good job of hosting Linux software unless each Linux virtual machine was updated with Hyper-V drivers. While this might sound like a reasonable proposition to some, many firms run customised Linux code that can’t be modified without a huge amount of effort. In some cases the effort involves having Linux experts recompile the each Linux kernel to include the new driver software. In others, it’s about re-validating the modified platform so that third party software vendors would continue to support it. For the unlucky few, it involves both.
Microsoft’s move to embed its drivers in the Linux kernel would eventually solve those problems. However, it will take time before the Microsoft drivers are actually embedded in the Linux kernel, and several years more before the modified Linux kernel is adopted in mission critical server systems. After all, the owners of such systems are usually extremely conservative when it comes to changing systems that are working properly. The “if it isn’t broke don’t fix it” mentality normally reigns supreme. Ironically, virtualisation helps keep software running even longer than if the software is hosted directly on physical server systems. This is because features such VMWare’s vMotion and High Availability mean servers don’t need to be taken off line because for hardware upgrades or maintenance. The VM can simply be migrated to another hypervisor.
For an indication of just how bad Hyper-V currently is at running Linux software, take a look at benchmark results published by The Hypervisor last year. Our tests showed VMware software ran basic Linux code more than six times faster than Hyper-V. Our tests were fairly simple, but crucially we did not install any optimised drivers into the virtual machines being tested. These are exactly the kind of optimised drivers Microsoft is now trying to add to the Linux kernel. By the time the Microsoft drivers are added, we expect Hyper-V to fare better in such tests.