Want to have your server sync to a public time clock so it can keep accurate time? Here is how it’s done:
First, you need to make sure you have the time zone setup as you like. I set all of my servers to my timezone, regardless of where the server actually is. This makes finding information in logs easier. Many people specify UTC or GMT time. This is a considered best practice, especially for enterprise level servers. Most of our customers are smaller and have only 1 or 2 regions, so we will use our time zone (because we troubleshoot their issues and it makes it easier on us).
Specify Time Zone
(1:99)# dpkg-reconfigure tzdata
Current default time zone: 'America/Chicago'
Local time is now: Thu Feb 5 04:30:44 CST 2015.
Universal Time is now: Thu Feb 5 10:30:44 UTC 2015.
Set Approximate Initial Time
(1:99)# /bin/date MMDDHHMMCCYY
(1:99)# /bin/date 020504312015
Thu Feb 5 04:31:00 CST 2015
Update the NTP pool
We add 3 NTP servers to the pool so it can check more reliably
(1:101)# ntpdate 0.north-america.pool.ntp.org
5 Feb 04:35:34 ntpdate[2890]: adjust time server 132.163.4.102 offset 62.967271 sec
(1:101)# ntpdate 1.north-america.pool.ntp.org
5 Feb 04:36:18 ntpdate[2897]: adjust time server 74.207.242.71 offset -0.004201 sec
(1:102)# ntpdate 2.north-america.pool.ntp.org
5 Feb 04:36:59 ntpdate[2903]: adjust time server 199.182.221.110 offset 0.001515 sec
Update System Clock
This doesn’t work on a virtual machine or VPS, but on a standalone, it does:
hwclock --systohc --utc
Verify NTP is working
You can install the ntp client, though this isn’t required:
(1:106)# apt-get install ntp
(1:106)# ntpq -p
remote refid st t when poll reach delay offset jitter
==============================================================================
time-c.nist.gov .ACTS. 1 u 3 64 1 73.392 -2.196 0.000
wotan.tuxli.ch 91.189.89.199 3 u 2 64 1 162.693 -1.093 0.000
lyla.preshweb.c 129.215.160.240 3 u 1 64 1 161.516 1.594 0.000
a1.pcloud.com 200.98.196.212 2 u - 64 1 54.421 -1.160 0.000
golem.canonical .INIT. 16 u - 64 0 0.000 0.000 0.000
Or you can simply look at your syslogs:
(1:108)# cat /var/log/syslog | grep ntp
Reboot
Services will need to update logs with the new time, and the most reliable way to do this is to reboot the server.