Time Drift?

General support questions including new installations
abudzynski
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Joined: 2017/02/27 14:37:25

Time Drift?

Postby abudzynski » 2017/02/27 14:44:58

I run CentOS 5 in VMware Fusion 8.5.3. Works great. Was having issues with the clock in CentOS 5 drifting (we're talking 8-10 hours of drift after being fine the day before). So, instead of having CentOS 5 sync to the timeclock of the VMware host (proper time) I setup CentOS 5 to sync to an NTP server.

Issue still occurred. So, I decided to check VMware time sync settings: CentOS WAS set to sync with the VMware host's time clock. I turned this off and only let CentOS run off of the NTP sync.

Issue resolved, for now. Until the time drift occurred again (and somehow NTP was turned off). CentOS 5 never restarted, uptime was mutiple days. Not sure why NTP would just turn off?

Realized VMware Tools wasn't installed. Installed VMware tools and CentOS 5 started being MUCH more responsive and started behaving much better. At this point I only enabled NTP sync and turned off VMware time sync (with host).

The issue happened again over the weekend. Logged into CentOS 5, time was off by 10 hours and NTP was turned off. VMware settings were set so that CentOS would NOT sync its time with the VMware host.

So, now I've just set CentOS to sync its timeclock with the VMware host : NTP is turned off in CentOS.

So far so good but its only been an hour..

Why so much drift?! 10 hours? It was fine on Thursday and then on Friday it just all of a sudden switched.

Timezones are fine.... in fact the drift is more like 10 hours and 17 minutes.

Very odd. We'll see if turning off NTP sync in CentOS / turning on time sync in VMware fixes the issue?

Aye aye aye.

Thanks for any insight.... im hitting my head into a wall with this one

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avij
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Re: Time Drift?

Postby avij » 2017/02/27 15:56:25


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TrevorH
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Re: Time Drift?

Postby TrevorH » 2017/02/27 17:27:06

The ntpd daemon will just stop and exit if the time difference is more than the threshold (by default 1000s but probably modifiable).

The VMware setting cannot be changed by CentOS so I'd be looking at your fellow workers to find out who is changing that. VMware tools might (probably) need reinstallation after a kernel update and there have been 2 of those for el5 in the last week or two. Perhaps your system is set to automatically install them and reboot itself afterwards?

I'm off to edit the forum notification to show that el5 now only has one more month of life left...
CentOS 5 died in March 2017 - migrate NOW!
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MartinR
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Re: Time Drift?

Postby MartinR » 2017/02/28 10:19:35

Not sure quite how relevant this is, but cast your eyes over
https://www.centos.org/forums/viewtopic ... 16&t=61186
My issue was with suspended VMs failing to jump forward when reactivated.