All Things PerfectDisk – and Defrag - Saved One Guy a Bundle

I was recently invited to speak at a VMware User Group meeting about the impact of file and free space fragmentation in a virtual environment. Before I started the presentation I asked the audience how many had ever defragmented a physical server and about 30% raised their hand. Then I asked how many had ever defragmented a virtual server and about 10% raised their hand. This is a pretty typical response.

Systems administrators running virtual machines seem to overlook the fact that each virtual machine is running its own version of Windows Server and within that machine NTFS is busy fragmenting files and free space. While fragmentation is a performance-stealing problem on physical servers, the problem is compounded on virtual machines where each virtual instance is competing for a finite amount of resources. This leads to resource contention between Windows guests and, with Hyper-V, contention between the Windows guests and the host. It is essential to keep the files defragmented and the free space consolidated on Windows guests to maximize performance and minimize resource contention in a virtual world.

After my presentation one attendee told me his company was having performance issues with several of their virtual servers. They were looking at upgrading the hardware and bringing in a consultant. He knew these virtual machines were frequently updating files, the kind of activity that produces fragmentation, but he never thought of fragmentation as the problem. After sitting through my presentation he was convinced fragmentation was the culprit and we just saved them a lot of unnecessary expense. In complex technical environments it is easy to overlook the obvious when looking for a solution. Sometimes you just need to defrag a computer to get a lot more out of it, and that includes VM's.