CentOS7的にデフォルトはchrony。ntpdも使えますがどちらかのみ。
ntpdを殺して、chronyを使う場合
# systemctl stop ntpd.service # systemctl disable ntpd.service # systemctl start chronyd.service # systemctl enable chronyd.service
# chronyc sources 210 Number of sources = 1 MS Name/IP address Stratum Poll Reach LastRx Last sample =============================================================================== ^* 192.168.248.224 2 6 377 33 -29us[ -68us] +/- 16ms
ntpdの場合
# systemctl stop chronyd.service
# systemctl disable chronyd.service
# systemctl start ntpd.service
# systemctl enable ntpd.service
chronydを殺す。設定は略（ぁ
# ntpq -p
remote refid st t when poll reach delay offset jitter
==============================================================================
*ntp-b3.nict.go. .NICT. 1 u 26 64 377 23.085 -0.216 21.137
*おまけ chronyの設定
# cat /etc/chrony.conf
server ntp.nict.jp iburst
driftfile /var/lib/chrony/drift
makestep 3.0 3
rtcsync
allow 192.168.0.0/16
allow 172.16.0.0/12
allow 10.0.0.0/9
port 123
cmdport 0
acquisitionport 123
logdir /var/log/chrony