Article ID: 119952, created on Feb 2, 2014, last review on May 9, 2014

  • Applies to:
  • Virtuozzo 6.0
  • Virtuozzo hypervisor

Symptoms

  1. Guest operating system does not boot if more than 1 CPU is assigned to the virtual machine.
  2. While the virtual machine is running, corresponding prl_vm_app process shows >200% CPU usage.
  3. Guest operating system boots properly if only 1 CPU is assigned to the virtual machine or if more than 1 CPU is assigned and kernel.invariant_tsc=0 boot flag (system flag) is passed to the virtual machine.
  4. The error message can be seen in the /var/log/messages log on the node:

    Marking TSC unstable due to check_tsc_sync_source failed
    

Cause

The problem is most likely caused by the hardware issue, like incorrect information provided by BIOS about time stamp counter (TSC) support by CPUs.

Resolution

Update BIOS in the system.

If BIOS update does not fix the problem, contact hardware vendor, reporting that the motherboard/CPU information contains incorrect data about invariant TSC.

Search Words

invariant tsc

Marking TSC unstable due to check_tsc_sync_source failed

X79A-GD65 (8D)

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