vmware Archives

VMware Fault Tolerance, Determinism, and SMP

April 19, 2011 by Bob Plankers

We’re all at least roughly familiar with Fault Tolerance, a feature VMware added to vSphere 4 to establish a mirrored VM on a secondary host. It’s kind of like RAID 1 for VMs. To do this, Fault Tolerance records the inputs to a primary VM, and then replays it on the secondary VM to achieve the same results. There are two important and somewhat subtle points here that help us understand why Fault Tolerance is limited to one CPU. First, the process records the inputs, not the state of the PC after the inputs happen. If you moved the mouse on the primary it moves the mouse on the secondary VM in exactly the same fashion. If you ping the …

Why Internet Explorer 9's Power Consumption Matters

April 7, 2011 by Bob Plankers

Microsoft blogged about how they worked to reduce the power consumption for Internet Explorer 9: Power consumption is an important consideration in building a modern browser and one objective of Internet Explorer 9 is to responsibly lead the industry in power requirements. The more efficiently a browser uses power the longer the battery will last in a mobile device, the lower the electricity costs, and the smaller the environment impact. While power might seem like a minor concern, with nearly two billion people now using the Internet the worldwide implications of browser power consumption are significant. As a virtualization guy I watch power consumption & battery life work closely. Almost universally, their work to extend battery life also means lower utilization …