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Questions tagged [time-synchronization]

The tag has no usage guidance.

0
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2answers
107 views

What sources does public NTP servers use to ensure time sync?

As from the title, I would like to know what sources “pool.ntp.org” and other big NTP service providers use in order to ensure they are in sync and serving clients the exact date and time.
0
votes
1answer
21 views

Query Network Client Date

Question: Is there a way to ping or query the date of a client linux computer for the purpose of verifying time synchronization? Setup: I have two computers on a network. One linux machine (machine A)...
0
votes
1answer
276 views

How do I force a domain controller to sync with the PDC?

DC2 (a VM) is not syncing to DC1 (a physical server). On DC2 I get: PS C:\> w32tm /query /source Local CMOS Clock What must I do so that DC2 syncs to DC1 as its time source? Background: I had ...
2
votes
2answers
188 views

Decentralized NTP in network with only sporadic internet connectivity?

I have a (most of the time) isolated network consisting of several computers. computer 0 -- external NTP server / switch -- computer 1 -- external NTP server \ ...
3
votes
1answer
54 views

Compute Engine VM clock runs fast and gains 15 seconds per hour (or about 1 second per each 4 minutes)

I have a 2 vm instances in GCE that do not keep correct time in spite of the server OS being set to sync with NTP every 24 hours. The OS clock gains about 1 second of time every four minutes (or ...
0
votes
1answer
119 views

2008r2 clock running fast

I have 27 2008R2 servers (all Hyper-V guests) that recently started running fast. There are other 2008R2 servers on the same hosts that run spot on. The time averages from 2 to 3 minutes fast but at ...
0
votes
3answers
95 views

Properly setting date on Linux machines

I am trying to set the system date on my linux machine. If it matters, it is an Amazon EC2 machine that I provisioned. I tried to set the date with this command: sudo date -s "19 APR 2018 11:14:00"; ...
5
votes
3answers
476 views

Ntpd on local network - Preventing clock drift causing high offsets

I have a local network with a microcontroller ARM as the NTP server and I have a desktop computer running with ubuntu 16.04 LTS as a NTP client. Once I start ntpd -g -c /etc/ntp.conf with the ...
1
vote
1answer
1k views

EventID 1 - An application or system component changed the time

Our VM's are coming up with the following errors in the Event Log - EventID 1 Change Reason: An application or system component changed the time. All the DC's look to be time synced correctly, but ...
4
votes
0answers
485 views

Why did w32tm /resync cause it to correct itself, then overshoot?

Background: My LAN's Windows Server 2012 R2 Domain Controller had been running without any external time server for a few years and I finally synchronized it now. It had been running about 2 minutes ...
12
votes
3answers
2k views

How to synchronize time on ESXi Windows virtual machines within one second?

I'm a developer and we are using Quartz.Net, widely used scheduling library with SQL backing store to run cluster of jobs servers (VMs on ESXI cluster). Quartz.Net requires that time will be ...
8
votes
2answers
194 views

linux system time temporally jumps

I saw a strange system time changing behavior in some (hardware) servers: in /var/logs/syslog, the date time preceding each log message sometimes change to a random one and gets back to normal in the ...
0
votes
3answers
3k views

Domain Controller time won't sync with NTP server

I'm having a problem with a domain controller which won't sync with a time server. I've tried everything I can think of and I've already googled many fixes, but nothing seems to work. This is a ...
1
vote
2answers
544 views

Unable to synchronize date by NTP on Debian 9

Debian 9 as Guest Hyper-V is unable to synchronize the clock and set the right date, always it stays around 6 minutes behind: (Timezone is obfuscated) #  systemctl start ntp #  date sáb jul ...
1
vote
2answers
4k views

change time grayed out in windows server 2016

I have Windows server 2016 joined to domain. I want to put back date in the server. But the option for changing date and time is grayed out. It has a message saying "Some settings are hidden or ...
0
votes
2answers
2k views

How do I tell if chronyd is actually self-synchronising correctly?

I'm working on some devices where I want them to self-synchronise while their network connection is down (i.e. use chrony's calculations of drift rates to compensate for system clock drift), and then ...
3
votes
1answer
85 views

How to prevent relative time shift after restoring a snapshot in Parallels?

I am working with a web-based app on an Ubuntu test/development system running in Parallels. At specific dates and times (taken from the system time) some events happen and things are changed in the ...
2
votes
1answer
382 views

Clock drifts on virtual machine, nothing helps

I have very rapid time drifts on vmware. -241587 20:38 -241587 20:39 -241587 20:40 -241587 20:41 -241587 20:42 -0.014 20:02 -0.025 20:03 -0.056 20:04 -0.093 20:05 -0.093 20:06 -68996. 20:07 -68996. ...
3
votes
2answers
368 views

How to do proper VPS timekeeping?

I'm configuring a VPS to log some time-series online data and I notice that the time is off. I'd like to have better than 10 second precision on this. I read somewhere that VPS timekeeping is ...
2
votes
2answers
501 views

Find windows process that is changing time back 1 hour

I have a windows machine which will periodically change the system time, for reasons unknown. It appears to happen every hour. This windows machine is a virtual machine (Parallels Desktop 9, Win7 ...
0
votes
1answer
1k views

How to enable NTP module CentOS 7?

I have one server running CentOS 7 to install ntp module I followed the below steps: yum install -y ntp systemctl start ntpd systemctl enable ntpd systemctl status ntpd timedatectl set-timezone ...
0
votes
1answer
308 views

Does systemd-timesyncd need to listen to random UDP ports to work properly?

On Debian Jessie servers I see systemd-timesyncd listening on random UDP ports. Which is not the case on Debian Stretch hosts. By random I mean the port it listens to varies from server to server. ...
0
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1answer
104 views

Why is my internal clock always 1.3 seconds off?

I ran w32tm /stripchart /computer:time.windows.com just for fun and found out that my clock is 1.3 seconds behind this timeserver. Not that I think Microsoft is wrong, but I tried it with various ...
0
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2answers
268 views

System time is off by up to hundreds of milliseconds despite NTP sync before boot

I'm running a couple of servers which need a pretty tight time sync (<50ms) as they are running a Paxos algorithm. The servers are running NTP and are successfully sync at one point. According to ...
2
votes
3answers
289 views

How to properly sync time for 3 Hyper-V machines, with Host NOT on domain of the VMs?

I understand that for production use, if you have a Hyper-V Domain Controller VM, and the host is on the domain as well, you should have the DC VM reach out to an external source for date/time, and ...
1
vote
1answer
252 views

Timesyncd with NTP server using md5

I have a FreeBSD server used as an NTP server with md5 as authentication. If I want to connect to it from a FreeBSD/Linux machine which has ntpd, I can simply add something along the lines of server ...
0
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2answers
423 views

Chef-Server 12 Getting me errors when the node is not time synced

I'm getting this error when the clock on my node is different than 15 minutes from my chef server. Authentication Error: Failed to authenticate to the chef server (http 401). enter code here`...
2
votes
2answers
348 views

Keeping server time in sync using ntpd

I understand ntpd has a -g option to allow a one time immediate clock set for large skews. Then the daemon runs and continuously adjusts. In the event of the skew becoming too large, the daemon exits ...
1
vote
0answers
488 views

How to configure ntp server and chrony client for time sync over link-local IPv6

I have two computers connected with an Ethernet cable. The first computer, let's call it the "master" is also connected to the Internet via a wireless network. It's running ntp and getting its time ...
2
votes
3answers
573 views

How accurately are aws clocks synchronized between different aws regions?

According to the wikipedia NTP article, NTP is accurate within 10ms over public internet. I would like to maintain accuracy of logs/events across different AWS regions and my question is how ...
1
vote
1answer
1k views

no internet time tab on domain controller, Windows Server 2016

I got an ActiveDirectory with one domain controller that run on Windows Server 2016. I set everything up and most of the things run perfectly so far. But now and then when we have to take it offline, ...
0
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0answers
51 views

How to read VMware interrupt backlog?

The VMware document titled "Timekeeping in VMware Virtual Machines" have the following referente to the issues with the time drift: If the virtual machine is running too slowly, perhaps as a result ...
2
votes
1answer
2k views

NTP is running, Clock not synced. Manual DOES work

An ubuntu server is running ntp, and connected to the internet. Still, the system clock is about 30 minutes wrong and gets bigger over time. $ service ntp status NTP server is running.. Output of ...
1
vote
1answer
39 views

Is there a link between frequent Virtual Server crashes and time synchronization

I am running a 4GB Virtual Server (VMWare) running Tomcat on Windows Server 2012 R2. The server is subject to unexplained restarts every two weeks or so. While searching the event log I filtered on ...
1
vote
1answer
706 views

Getting HTTP response with date before request date. Is that right?

Say I sent a HTTP request at Thu, 22 Jun 2017 10:30:30 GMT. Is it right if I got Thu, 22 Jun 2017 10:30:25 GMT in response Date header? Which could be the cause?
0
votes
1answer
1k views

Time is not synced in centos7.3

I have installed stock CentOS7.3, and install chrony yum install -y chrony systemctl start chronyd systemctl enable chronyd If I start CentOS, the time is not synced: $ timedatectl NTP enabled: yes ...
3
votes
2answers
9k views

hwclock: Cannot access the Hardware Clock via any known method

On a Debian server, I'm having problem with hwclock: $ hwclock --show hwclock: Cannot access the Hardware Clock via any known method. hwclock: Use the --debug option to see the details of our search ...
2
votes
2answers
2k views

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 ...
-2
votes
3answers
315 views

Incorrect Ubuntu server time [closed]

I use 14.04.1-Ubuntu. When execute date in command line, I get time which about 1 min different comparing Greenwich Mean Time or other source. I synchronized it using sudo ntpdate -s time.nist.gov few ...
3
votes
4answers
448 views

ntp.conf: Is it reasonable to rely on default server list, exposed in CentOS?

Every time I setup a new Linux host (CentOS, lately), expecially when such an host will have some roles within our small datacenter (around 100 hosts), I take care to: install the ntp package; add, ...
0
votes
1answer
619 views

Windows 10 eventually changes time to UTC

I have 9 Windows 10 clients for whom I can not set the time. I proceed to date and time, change the time to the current time and timezone and then within an hour the time reverts to what appears to be ...
-1
votes
1answer
2k views

Disable time sync from the PDC for one machine

I have a Windows Sserver 2012 PDC as virtual machine, I want to disable the time sync of its host with the PDC to avoid the loop. However I want to maintain the sync with all other machines. How to ...
1
vote
1answer
2k views

chrony and gpsd: socket or PPS connection

I've try to get high precision time from gps receiver GlobalSat BU-353s4 (/dev/ttyUSB0) through gpsd in Raspberry PI with ArchLinux. /etc/chrony.conf contains: refclock SHM 0 delay 0.5 refid NEMA ...
0
votes
0answers
289 views

Time propogates with an offset

The network is simple, Two Domain Controllers Servers Client Workstations Other Devices The primary DC is configured to synchronize time with NTP servers. The secondary DC and other Servers are ...
0
votes
0answers
247 views

Time synchronization delay between two different location servers in one forest

We have two servers which are located at different location. They are in one forest through VPN network. They are under same domain. In shorts, they control their user accounts in one active directory....
0
votes
1answer
256 views

Is it worth it to install VMWare Tools on a non-graphical Linux guest (Red Hat 7 hosting an Oracle server) [duplicate]

This came up because I was not able to activate the time synchronization function from the VCD. Most of what I've seen that discussed the benefits of installing VMWare tools looks like it applies to ...
2
votes
2answers
465 views

Why does my Ubuntu virtual machine hosted in Hyper-V power on with a date in the future?

I have several Ubuntu virtual machine running within a Hyper-V server. The server is a Windows 2012r2 machine. The Ubuntu VMs are either Ubuntu 14.04 or Ubuntu 16.04 (the current LTS releases). ...
6
votes
1answer
21k views

How to set up local ntp server without internet access on ubuntu?

I have tried several guides on how to set up a local ntp server on ubuntu but none seem to work correctly. My servers are drifting heavily in time for some reason and I have to keep their time close ...
2
votes
1answer
95 views

PDCe won't accept external time source

I noticed our PDCe is running 1:20min late and, of course, also the rest of devices in the network. I'm trying to sync with an external time source but it's not going well. It's a virtual Windows ...
0
votes
0answers
51 views

Ubuntu CDT time lags by 1.5 min

My servers are Ubuntu 14.04 on AWS. Our application actually needs time in CDT. By default it was UTC, so I created a sysm link for localtime. ll /etc/localtime lrwxrwxrwx 1 root root 27 Sep 14 03:53 ...