VMware ESX Server 3.0.3, ESX303-200910401-BG: Updates VMX (1014759)
Release Date: October 16, 2009
This patch resolves a time gain issue for various Windows guest operating systems. Windows operating systems use multimedia timers that repeatedly switch the frequency of the CMOS periodic timer. This switch in the frequency interferes with the correct timekeeping in virtual machines, resulting in potential time gain.
Windows multimedia timers are a service provided by Windows operating systems to applications that provide high resolution callbacks for applications. Enabling, disabling, or changing the rate of callbacks can cause Windows to change the rate of interrupts requested from the hardware timer. The act of changing the rate of the hardware timer can cause small amounts of time to be gained. If the rate is changed frequently, an appreciable amount of time might be gained in the virtual machine. Java applications commonly change the multimedia timer rate and might trigger the time gain issue. The time gain issue has also been observed with the use of WebLogic.
Patch Download and Installation
Note: All virtual machines on the host must be either shut down or migrated using vMotion before applying the patch.
See the vCenter Update Manager Administration Guide for instructions on using Update Manager to download and install patches to automatically update ESX 3.0.3 hosts.