As of a major version ago on ESXi, it was considered best practice to run ntpdate in a cron rather than ntpd on VMs, particularly if you weren't using the most up-to-date VMware tools (and I believe they recommended the VMware version, rather than open-vm tools).
I've also seen that behavior when a VM Host had a screwed up NTP config. I haven't noticed any significant clock skew during a vmotion, but I've never checked it. I can give it a shot if you'd like. --Matt On Tue, Nov 18, 2014 at 4:50 PM, Mathew Snyder <[email protected]> wrote: > We are currently in a situation where we are being pressured to > re-engineer our NTP service. We currently host it, along with other > services, on Windows DCs. Our initial plan is to move NTP off of those > servers and host it on dedicated Linux servers. > > We likely won't get approval for hardware to host NTP and will thus have > to rely on VMs. This poses a few concerns such as: How will a Vmotion > affect the service? What happens if access to the sources that we use is > lost (for whatever reason)? > > In the past, all of our VMs would run ntpd normally. That is, as a > constantly running daemon.. However, we found that time was drifting > significantly to the tune of several seconds a day on several servers. We > never figured out why it was happening. Instead, we found that using a cron > job which runs /usr/sbin/ntpd every five minutes kept time synced up > nicely. We haven't had any issues since. > > However, now Red Hat is telling us we should (need) to be running ntpd as > a daemon because they are seeing timing issues. Interestingly, this was > never brought to the attention of us platform engineers so I don't know how > bad the problem is or how many servers are affected. > > The problem could be VMware Tools conflicting with ntpd. But again, we > don't know what the problem is. Only that we have a workaround-type > solution that we're being told we have to replace. > > This leads to my question to the list: those of you who have cloud > environments based on VMware solutions, how do you keep time in sync? What > issues have you encountered and how did you solve those problems? What can > you recommend for a virtualized NTP solution? > > > -Mathew > > "When you do things right, people won't be sure you've done anything at > all." - God; Futurama > > "We'll get along much better once you accept that you're wrong and > neither am I." - Me > > _______________________________________________ > Tech mailing list > [email protected] > https://lists.lopsa.org/cgi-bin/mailman/listinfo/tech > This list provided by the League of Professional System Administrators > http://lopsa.org/ > >
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