Questions tagged [time-synchronization]
The time-synchronization tag has no usage guidance.
256
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How do I update a CentOS server's time from an authoritative time server?
I have CentOS machine and each time I've noticed that the server loses correct time after a while. It is usually behind by several minutes after time passes from having manually set the correct time. ...
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42
votes
4
answers
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Windows Server unable to synchronize NTP time reliably
Why does Windows Server (2008, in this case, but I've seen the same problem in 2003) seem to have problem synchronizing time? I've seen this error in my System log across a variety of servers:
The ...
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37
votes
12
answers
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Is anyone using GPS for time sync?
I've come across a handful of GPS NTP servers, as well as some inexpensive solutions using off-the-shelf receivers and software. Right now I'm just using NTP with a list of servers over the Internet. ...
36
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6
answers
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Why is it important that servers have the exact same time?
I have read multiple times (although I can't find it right now) that data centers take great effort to make sure that all server have the exact same time. Including, but not limited to worrying about ...
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3
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NTP is running, system clock still not in time - what gives?
A Debian Stable (5.0.3) server is running ntpd, and connected to the internet. Still, the system clock is about 5 minutes wrong.
$ /etc/init.d/ntp status
NTP server is running..
Relevant parts (I ...
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22
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6
answers
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How to keep time on resumed KVM guest with libvirt?
On my host I am using libvirt and a KVM guest. When the host is shutting down, libvirt suspends the guest. When the host is starting up, libvirt resumes the guest. The problem is, if the guest is ...
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14
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4
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How to set a frequent period for NTP client to sync with the NTP server
I've setup an NTP client for my DC to sync time with time.windows.com but I want it to query the NTP server at least twice a day. I made all the changes via the registry, is there a period registry I ...
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14
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2
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What can be done to improve time synchronization on networks with sporadic internet access?
I'm looking for advice setting up time servers for a very non-typical network. I support many closed networks that have occasional access to the internet. A network would get access most days for a ...
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13
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3
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How to change time source from "Local CMOS Clock" to "DC"
In a domain, I want to set DC as time server.
To do that I use this command:
w32tm /config /manualpeerlist:europe.pool.ntp.org /syncfromflags:manual /reliable:yes /update
and
w32tm /resync /...
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9
answers
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12
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3
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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 ...
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11
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3
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Timesync on HyperV with CentOS 6.2
I've got a CentOS VM (release 6.2) running under HyperV. I have integration services installed (part of base now), and CentOS shows the current clocksource is hyperv_clocksource, however my time in ...
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11
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3
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How come one of my switches is off by two minutes in spite of ntp?
I just noticed by pure chance that one of my Cisco 4500 switches has its clock going wrong: it is more than 2 minutes behind in spite of seemingly functional ntp. In my opinion, even a single second ...
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votes
7
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Hyper-V Machine drifts time all over, even with NTP
Resolved
The problem was Hyper-V on that machine. I removed Hyper-V, installed VMware Server, ran the same VM. Time sync issues went away (< 100ms difference after a day).
My setup is like this:
...
- 1,739
10
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1
answer
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Ubuntu 20.04 time sync problems and possibly incorrect status information
I have been having some problems with crashes on my KVM host (Lubuntu 20.04), and when troubleshooting, I noticed some time-related errors.
Upon further investigation, to my horror, I saw that time ...
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What consequences / implications can arise from a wrong system clock?
What issues can you think of that may arise from a wrong system clock setting ?
Primarily interested in potential problems affecting servers and Linux or UNIX-like systems in particular.
And how ...
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3
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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 ...
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8
votes
1
answer
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NTP not syncing, only syncs on service restart
My ubuntu 11.10 server has been sitting there quite happily for the last 3 - 4 months, then suddenly the time started going out of sync by one hour. I'm not sure why, nothing has changed re the ...
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votes
2
answers
2k
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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 ...
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2
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Active Directory Time Synchronisation - Time-Service Event ID 50
I have an Active Directory domain with two DCs. The first DC in the forest/domain is Server 2012, the second is 2008 R2. The first DC holds the PDC Emulator role.
I sporadically receive a warning ...
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2
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how to auto-run ntdpdate command?
I have a few dedicated servers and for some reason they are totally unable to mantain the time properly synchronized, every few days they start having differences of minutes in the clock. So I have to ...
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4
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How to synchronize the clock of a windows server 2003 domain server?
Given a windows server 2003 domain server, I'd like to sync it's time to (any) external time services (it's off a couple of minutes). How to do this 1, manually; 2, in an automated manner every week?
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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 ...
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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 ...
- 2,163
6
votes
2
answers
2k
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Time synchronization in an heterogeneous environment
In a mixed environment, where machines can be running under Windows (most), Linux (a few), sometimes Android ... what is the best solution to have time synchronization with an accuracy close to ...
- 163
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votes
2
answers
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Allow Active Directory users to disable datetime sync
I have recently migrated my company to Active Directory. With it comes a default setting that will force time synchronization to be enabled.
Trouble is, some users need to change their datetime ...
6
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1
answer
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Is timesync still required for Windows Server 2012 R2?
Our servers are on a workgroup, we are a small company and do not use a domain controller. In Windows Server 2008 R2 we used TimeSync to help keep the most accurate time, not sure it was really ...
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1
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Can't access some clients using w32tm /stripchart - error: 0x800705B4
I'm trying to track down a time synchronisation problem. I've got a DC in a remote branch.
w32tm /dumpreg /subkey:Parameters reveals Type = NT5DS and the Type means its sync'ing with the domain, I ...
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How can I check if my time sync is correct?
I have updated a W2K3 settings according to the steps shown here:
http://support.microsoft.com/kb/816042#LetMeFixItMyselfAlways2
The peers list I use is:
0.asia.pool.ntp.org,0x1 1.asia.pool.ntp.org,...
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Is it possible to increase the rate at which ntpd updates the system clock?
We have some hosts that have gotten out of sync due to ntpd being mis-configured, with an ntp server that was unreachable. Our clocks on some hosts (CentOS 6) are now upwards of 30 seconds off (in the ...
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2
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NTP: How to establish redundant solution for NTP servers?
In my company's infrastructure there are 5 data centers in remote locations.
In each remote location, there's a pair of servers which hold DNS and NTP services and are configured on each one of the ...
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5
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1
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w32tm /resync not working instantly
This Question is mostly for other people to learn from and to satisfy my own curiosity if someone knows why it does the following.
We had a problem with our DC not having the right time due to it ...
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2
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Reliable Time Protocol Server Online?
I have some OLD legacy hardware that I'd like to keep time synchronized on. It supports the TIME protocol (not NTP). Are there any reliable TIME servers online anymore? If so, where?
-M
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Chrony doesn't appear to be syncing with the servers I've specified
I have set Chrony to sync with 4 NTP servers (config file below). When I run chronyc tracking and chronyc sources, it looks like the servers my machine is connecting to for NTP are not correct. I'd ...
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What increments stratum in NTP?
Sorry, it's just not that clear to me from the man pages, Wikipedia, etc.
I understand the concept of stratum 0 as an authoritative time source and stratum 1 as the connected server. However, I am ...
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1
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How to disable time synchronization on hyper V
I have test machine on hyper v (only for test purposes so I can do with it whatever I want to), it is ws 2008 r2 x64. I need to change date to 2008 year in order to test some scenarios with expired ...
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1
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Correct time drift throughout entire Windows domain
I have done a lot of research but failed to find a reliable answer to our problem.
The short story is our entire Windows domain is running 35 minutes slow. I.e. servers and workstations. I think ...
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2
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How to fix time on NTP server with a lot of machines synchronized by it
I have one NTP server which has a wrong time setting which are 7 hours in the future (timezone was changed after machine shipment, but not the time). The server itself is not synchronized, but only ...
5
votes
1
answer
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Why won't my domain server (2008 R2) sync with external time service correctly?
I have configured my PDC (windows 2008 R2) to sync with external time source uk.pool.ntp.org and followed all the instructions to the letter which are set out here:
http://blogs.technet.com/b/...
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Why is the time on my Server 2008 R2 DC wrong? It's syncing to ntp.org, it claims
OK. After a lot of fun with syncing time across my workstations, I got that sorted out. My workstations are now perfectly synced with my Server 2008 R2 Domain Controller (physical server, not virtual)....
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4
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Sync ntp immediately at boot with undiciplined clock
I have setup one ntp server and 5 clients. I want to force sync the clients to server clock on boot. With my current ntp settings the computers are syncing but after several minutes. I cannot wait so ...
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Increasing time difference between Windows Server 2003 and time.nist.gov even after explicitly syncing time
I have synced the time of my server to time.nist.gov. This server communicates with a client’s server which is also synced with time.nist.gov.
After noting that we seemed to be out of sync with the ...
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Best way to synchronise the time on a Windows 2008 Server
I have a small Windows domain (all servers running Windows 2008), with a single Windows 2008 Domain Controller. What is the best way to synchronise the time across all servers with an Internet Time ...
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2
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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 ...
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2
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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 ...
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Windows Server Time-Service jumps into the future and (partially) back
This looks like the same issue as Windows Server 2022 Time Service Jumping into the future.
I've also added a support ticket at Microsoft (Feedback Hub) for the issue: https://aka.ms/AAkwnpl
As the ...
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How do I re-enable the VM IC Time Synchronization Provider for a Hyper-V client?
We have a Windows domain network with 2 Hyper-V hosts. On these hosts, there are several Hyper-V VM clients. Two of these clients are Domain Controllers.
The Hyper-V hosts are both clients of that ...
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Windows Server 2008 - inexplicable system time jumps/glitches/inaccuracies
I'm running a production web server on Windows Server 2008. On this server I have a database which logs certain user actions, but every now and again I inexplicably get database entries which, ...
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KVM guest time shift on host reboot
I have installed Ubuntu server 12.04 as a KVM host, and created an Ubuntu guest that is also running Ubuntu server 12.04. The servers are in the AST time zone which is UTC + 3 hours. After setting the ...
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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 ...
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