I'm using CentOS 5.3 and VMware Server 2.0.1 is installed.

I discovered that the Linux system time is slower than BIOS time a lot. I run ntpdate and hwclock -w to obtain and save the accurate time about 21 hours ago, but now the Linux time is slower than the BIOS time about 7 minutes. It's abnormal.

$ date
Tue Oct 27 21:43:45 HKT 2009
$ /usr/sbin/hwclock -r
Tue 27 Oct 2009 09:50:30 PM HKT -0.003752 seconds


I have searched this problem in Google but their problem only occurs in Guest OS but my problem occurs in Host Linux OS.

Anyone encountered this problem before?
Does VMware slow the time? Or is it the wrong configuration of other application?

My English is not good I hope you can understand. Thanks!

Hi there, yes VMware machine clocks are notoriously bad ... but there are solutions, the vmware tools package will help greatly.

For the vmware host there should be no real issues, but setup NTPd to keep it on track.

Thanks for your reply

But the Linux system time is slower than the BIOS time (accurate time) a lot. Is it normal?

I run ntpdate and hwclock -w few hours ago but the Linux time now is slower than the BIOS time for 3 minutes.
# /sbin/hwclock -r
Wed 28 Oct 2009 11:25:36 PM HKT -0.469237 seconds
# date
Wed Oct 28 23:22:23 HKT 2009

Hi

Run it in a cron job, as often as needed.

Is it normal ? It is certainly well reported on the net, newer products are improved, e.g. ESX3.5 + vmtools seems to keep time well. I imagine they just keep checking and adjusting the clock more often, but the actual issue of clock skew has never gone away as far as i know.

Hope that helps

what are the time sources you use on the host OS? jiffies is the default in RHEL5, but you might want to try something else, like hpet, and see if that helps

After I updated the BIOS and enabled hpet, the problem has been solved.
Thanks