Time is critical when having many server and using different clusters. So i made this guide to save all my notes when working with time.
I make an link to /etc/timezone
ln -sf /usr/share/zoneinfo/Etc/GMT /etc/timezone
To check if i use the correct time zone
date
Ubuntu
apt-get install ntp
Centos
yum install ntp
Set up my ntp server for my other server. My ntp server is and ubuntu server
server 0.ubuntu.pool.ntp.org
server 1.ubuntu.pool.ntp.org server 2.ubuntu.pool.ntp.org server 3.ubuntu.pool.ntp.org
# Use Ubuntu's ntp server as a fallback. server ntp.ubuntu.com
#Allow ntp servers restrict 0.ubuntu.pool.ntp.org nomodify notrap noquery
restrict 1.ubuntu.pool.ntp.org nomodify notrap noquery
restrict 2.ubuntu.pool.ntp.org nomodify notrap noquery
restrict 3.ubuntu.pool.ntp.org nomodify notrap noquery
restrict ntp.ubuntu.com nomodify notrap noquery
# Local users may interrogate the ntp server more closely.
restrict 127.0.0.1
restrict ::1
#allow clients
restrict -4 default kod notrap nomodify nopeer noquery
restrict -6 default kod notrap nomodify nopeer noquery
restrict 10.10.0.0 mask 255.255.255.0 notrap nomodify <--- my local network
On my ntp clients i only set server to my ntp server ip
server 10.10.0.1
Restart ntp servers and test it
ntpq -p