Am 31.08.2012 16:58, schrieb Tom Grace: > On 31/08/12 15:34, Rainer Traut wrote: >> Am 31.08.2012 16:19, schrieb Tom Grace: >>> If the clock is wrong by (if I remember correctly) about 30 mins it will >>> take so long to drift back to being correct that NTPd gives up. >> >> Hmm, no it still does time resets in my tests iIf I set the clock -27s >> of timesource. >> This happens: >> Aug 31 16:30:14 aitcsdb002 ntpd[6062]: time reset +27.006389 s > > Ah, it turns out I was wrong about the 30 mins thing, that relates to > some other issue with NTP giving up and quitting if the clock is > drifting around too much. Thanks Tom and Dave for your answers. I double checked with real hardware - there it works - so this looks to me like a bug in ESXi5 running RHEL6/C6 and ntpd. We are running latest VMware ESXi5 patch 768111 and latest RHEL/CentOS. I followed VMware's best practices closely: http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1006427 Means, no time sync using vmware-tools, just ntpd with no local timesource. Rainer