topic VMware Linux guest time running fast in Operating System - Linux

VMware Linux guest time running fast

jedd — Tue, 28 Oct 2008 17:25:51 GMT

Hello all
I hope that somebody can assist. I have the following environment
ESX 3.5 Update2 running on DL585
SLES 9 SP4 x86_64 guest instance
SLES 10 Sp1 guest instance
I have SAP applications running on the instances.
Here is the problem, I have time server that is linked via which I use to synch my virtual instances. The ntp time synchs perfectly when the SAP application is not running. When I start the SAP application, the time starts running faster until it resets and I get SAP application dump. I have tried all recommendations between Novell and VMware to set kernel paramters e.g. clock=pit, notsc or ignore_lost_tics. I have only one time server in our environment. I know for a fact that it is not a time server issue since all of our physical machines are synching correctly to the time server. At this point, I really don't know where to look at anymore. Here is a sample of the *paltime.pal.sap result of the command xntpdc -p
10.48.162.172 1 64 3 0.00009 -8.376848 0.00607
any assistance would be appreciated

Re: VMware Linux guest time running fast

Ivan Ferreira — Tue, 28 Oct 2008 17:31:39 GMT

For vmware virtual machines, is not recommended the use of NTP. You must configure the vmware tools and set then to sync the clock with the host.

Re: VMware Linux guest time running fast

Uwe Zessin — Tue, 28 Oct 2008 19:15:56 GMT

VMware sometimes suggests not using VMware-tools for synchronization, e.g.:
http://kb.vmware.com/kb/1006427

""Note: In all cases use NTP instead of VMware Tools periodic time synchronization.""

Re: VMware Linux guest time running fast

Ivan Ferreira — Tue, 28 Oct 2008 19:37:35 GMT

Thanks Uwe, the document I have was outdated.

You provided the precise information.

Full description here:

http://www.vmware.com/pdf/vmware_timekeeping.pdf