Tag Archives: time sync

VMware / time sync with linux guests

In my default configuration, time was running way too fast in VMware linux guests. After spending hours of searching howto solve the problem, I finally found a few different points that might work as a solution.

Host: SuSE Linux 10.1
Guest: SuSE Linux 10.1
VMware Server: 1.0.2

  • Install the vmware-tools on the guest.
    Don’t forget to install the kernel-sources if you have to recompile some modules.
  • Insert clock=pit into the guest’s kernel boot options.
    When you’re using grub, it kinda looks like this:
    kernel /vmlinuz root=/dev/sda3 apm=off acpi=off clock=pit
  • Set tools.syncTime = “TRUE” in your virtual machine .vmx-file
    (found on the host machine [default in /var/lib/vmware/..])

    Your guest has to be rebooted to activate this setting.
  • Finally, I had to change a little thing on the host machine:
    Disable powersaved (or powernowd or whatever applies to you)

From that time on, my guests are perfectly in sync with the host’s time.

Note: Nov, 23th 2007: .. or not … time is still too fast on some virtual machines : (

Next thing I tried right now is to add the following lines in /etc/vmware/config:
host.cpukHz = 2200000
host.noTSC = TRUE
ptsc.noTSC = TRUE

Where 2200000 (2,2 GHz) is the max speed of the host cpu.

+ Updated to VMware Server 1.0.4
^^ At first sight, this works perfectly for me : )

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