/ informatica

VMWare clock syncronization errors

Using VMWare on a quad-core Intel(R) Xeon(R) CPU E5335 @ 2.00GHz with Ubuntu in /var/log/syslog on the host i got a lot of messages:

rtc: lost some interrupts at 128Hz
rtc: lost some interrupts at 256Hz
/dev/vmmon[26777]: host clock rate change request 123 -> 146

After some googlesearches i found the solution. In both case i had to edit the /etc/vmware/config file.

For the rtc error (from http://www.vmware.com/pdf/vmware_timekeeping.pdf):

host.useFastClock = FALSE

And for the clock rate (from http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1591):

host.cpukHz = 1995001
host.noTSC = TRUE
ptsc.noTSC = TRUE

To calculate the cpukHZ open /proc/cpuinfo:

~$ cat /proc/cpuinfo
cpu MHz : 1995.001

The value is in MHz, so multiply by 1000... :)