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Questions tagged [clock-synchronization]

61 questions
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AWS EC2 with huge clock drift at boot

We have an Amazon EC2 CentOS 7.5 instance whose clock, at boot, is always 35 days late. Yes, you read it correctly. That's a hell of a drift. [root@myec2 ~]# ntpd -gqn ntpd: time set +2937270.012860s Where does the machine fetches the current…
dr_
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NTP 'reach' resetting, wrong refid of remote ntp server, and high jitter

I've got a remote unmanned server that's been exhibiting some extremely strange clock/NTP behavior lately. Symptoms: Very high jitter ntpq -pn returns: A resetting 'when' count of back to 1, even though the NTP server is literally 1m of CAT5e…
EnemyBagJones
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FreeBSD: how to syncronize the system clock with the hardware clock in bash?

I am writing a script that synchronizes the system clock with the hardware clock (aka RTC, or CMOS clock) assuming that no Network Time Protocol (NTP) daemon is running. I am running in a virtual machine and the supervisor doesn't let the hardware…
Lilás
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RTC time is going totally wrong after a few minutes (Ubuntu 16.04 + Hyper-V)

My RTC time on my Ubuntu 16.04 is going crazy. After a few minutes the RTC time is going totaly wrong. The strange thing is, if I disable NTP Service (timedatectl set-ntp false and service ntp stop) and fix the time once (hwclock -w) the RTC time is…
Jerico
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system clock skewing backwards 112 seconds

I'm troubleshooting a problem on one of my NTP servers. This server seems to defy logic, and I'm at my wits end trying to troubleshoot it. Roughly every 162 seconds, the system clock reverts to (current time - 112 seconds), despite the hardware…
ben
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WS2008 NTP - Using time.windows.com,0x9 - Time always skewed forwards

I have a domain controller configured to use time.windows.com (with 0x09 flags set). I've noticed that frequently the systems' clock is fast - it varies from 10 minutes to even 45 minutes. I always have to keep resetting the system date/time back to…
Dai
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VMware: How to keep time in guest after suspend

I have Gentoo installed as guest OS. I have hardware clock synced with host system, but the clock of OS tend to be wrong after suspend. The only solution I find out is run hwclock -s frequently via cron. Any better method?
leafduo
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periodically overridding NTP for simulation purposes

I have this situation: NTP is used to sync time on a set of Windows 7 and Server 2008 machines. Nothing out of the ordinary about this. periodically on this system, the time needs to be changed for testing/training purposes (it is a training…
Gerard
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NTP failing to update

I am attempting to use ntp on the server. Checking ps the ntpd process seems to be running: ntpd -u ntp:ntp -p /var/run/ntpd.pid -g However the time is not being corrected, any ideas? The drift is about 2 minutes per month, which is not a problem…
Nick
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Chrony reporting system time slower than NTP and growing

I have chrony running on several of my instances. Unfortuantely, on one of them, it keeps reporting that the system time is slower than NTP time. This number of seconds keeps growing at a rate of about 10 seconds per minute. Here is one…
checklist
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How to configure hwclock to UTC on Redhat Linux?

I have linux redhat machine # more /etc/redhat-release Red Hat Enterprise Linux Server release 5.11 (Tikanga) I want to change the hwclock to UTC time So I perform little test as # date -u Tue Jul 26 10:01:53 UTC 2016 more…
dandan
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How accurate can we get computer clocks synchronized in a local network of any number of computers?

In the past, I have seen that most of my computer on my local network don't really have the same time within up to 1 second or so. So I wanted to make sure that it would be possible for a stack of servers (say 48 1U computers) to all have the exact…
Alexis Wilke
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How do I synchronize clocks between Linux and Windows?

I am running some benchmarks between a Windows client and Linux server. In order to measure the latency correctly I need to synchronize the clocks between the two machines before starting the test - ideally down to the nearest millisecond - what's…
Supertux
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Hardware Clock (RTC) Stuck / Will Not Increment

After we rebooted one of our servers (RHEL), we noticed that it would hang when entering GRUB. The problem was the countdown in GRUB (Booting in 5... 4......) was not counting down, and was stuck at 5. At the same time, we noticed that when…
Tanaki
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How to backdate a domain-connected workstation?

I need to verify some test cases by backdating my system. How to do this?
O.O
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