Matt,
If time is drifting on the VMs then you’re not pointing them to NTP servers that are staying in sync. Note that you should be using at least four NTP servers per NTP element to ensure good reliability. Frank From: tech-boun...@lists.lopsa.org [mailto:tech-boun...@lists.lopsa.org] On Behalf Of Mathew Snyder Sent: Tuesday, November 18, 2014 3:50 PM To: LOPSA Tech Subject: [lopsa-tech] Keeping time in sync in a VMware "cloud" environment 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 Tech@lists.lopsa.org https://lists.lopsa.org/cgi-bin/mailman/listinfo/tech This list provided by the League of Professional System Administrators http://lopsa.org/
