VMWare suggests you do NOT run NTP on the guest OS, only the master. You do not need your own ntp server to run ntp. If you go to the VMWare site and forums there are many discussions on clock scew. The way VMware virtualzes the system plays total havoc on the clocks. They might count slow or really fast, or jump forward and backwards. Also your terminology is confusing 'dom0' is a XEN thing ' guest os' is a vmware thing. It is hard to tell which product you are using. If you are using VMware and the clock is slow or jumping around refer to my first post. If you are XEN I can not help much. On 7/2/07, Maurizio Marini <maurizio.marini(a)cost.it&gt; wrote:

VM-ware somtimes has annoying clock issues. If you are using a VMware supported Kernel on a VMware supported OS you should be able to 'install vmware tools' - run the RPM be ok. I am on Fedora Core 5. This is what I have to do. My VMWare machines have I have found that using VMWare server with the stock FC5 kernel works and vmware 1.0.1 works 'OK' as long as: -You install VMware tools on the guest os -You turn on the real time clock in the configuration of vmware tools -You change clock=PIT in the kernel boot -You only use one processor for the system. Your milage on this may vary depending on what kernel / vmware combination you are using. With two processor emulation I found the clock totally irradic, and the host system was telling me about soft lockups. I found that for most things one processor emulation works well enough. Here is what I do: install kernel-source/kernel-devel In vmware click 'install vmware tools' This creats a pseudo CD device that you have to mount ( I do not remember how) In the psuedo cd-rom device there are two files VMware-Tools-1.0.1-(version).rpm and the tar I RPM install the tar download vmware-any-any-update105.tar.gz vmware-tools-any-update1.tar.gz tar -xf vmware-tools-any-update1.tar.gz tar -xf vmware-any-any-update105.tar.gz cp vmware-tools-any-update/runme.pl vmware-any-any-update/runme.pl cd vmware-any-any-update perl runme.pl Set clock=pit in kernel config Reboot Still, I find if the system is very busy I have found the clock jumping a minute and then jumping back. I still run ntp sometimes against suggestion of vmware. Then again I am not on a supported OS. On 7/2/07, Maurizio Marini <maumar.marini(a)cost.it&gt; wrote: