CENTOS 7 上設定 NTP 自動對時
1. 安裝 ntp 套件
sudo yum -y install ntp
2. 使用 ntpdate 測試 NTP 連線
這邊是用 pool.ntp.org 這個 NTP 伺服器,如果有其他的也可以指定~
執行完後,系統時間已經被調整成正確的了~
root@localhost ~ # ntpdate pool.ntp.org 11 Dec 12:29:55 ntpdate[5605]: step time server 61.219.119.37 offset 4928.479156 sec root@localhost ~ # date Thu Dec 11 12:30:00 CST 2014
3. 啟動 ntpd daemon
剛才做的 ntpdate 只是一次性的對時,要開啟 ntpd 這個 daemon 才能持續的對時,
用 systemctl start ntpd 就可以啟動 ntpd 這個 daemon,
啟動後用 systemctl status ntpd 看一下狀態,確定 daemon 起來了~
root@localhost ~ # systemctl start ntpd root@localhost ~ # systemctl status ntpd ntpd.service - Network Time Service Loaded: loaded (/usr/lib/systemd/system/ntpd.service; enabled) Active: active (running) since Thu 2014-12-11 12:52:58 CST; 4s ago Process: 9467 ExecStart=/usr/sbin/ntpd -u ntp:ntp $OPTIONS (code=exited, status=0/SUCCESS) Main PID: 9470 (ntpd) CGroup: /system.slice/ntpd.service └─9470 /usr/sbin/ntpd -u ntp:ntp -g Dec 11 12:52:58 localhost ntpd[9470]: Listen normally on 6 lo ::1 UDP 123 Dec 11 12:52:58 localhost ntpd[9470]: Listen normally on 7 enp0s3 fe80::a00:27ff:fe85:a70c UDP 123 Dec 11 12:52:58 localhost ntpd[9470]: Listen normally on 8 enp0s3 fd96:7568:9882:16:44f:7b56:a5f5:47f6 UDP 123 Dec 11 12:52:58 localhost ntpd[9470]: Listen normally on 9 vboxnet0 fe80::800:27ff:fe00:0 UDP 123 Dec 11 12:52:58 localhost ntpd[9470]: Listening on routing socket on fd #26 for interface updates Dec 11 12:52:58 localhost ntpd[9470]: 0.0.0.0 c016 06 restart Dec 11 12:52:58 localhost ntpd[9470]: 0.0.0.0 c012 02 freq_set kernel 0.000 PPM Dec 11 12:52:58 localhost ntpd[9470]: 0.0.0.0 c011 01 freq_not_set Dec 11 12:52:58 localhost systemd[1]: Started Network Time Service. Dec 11 12:52:59 localhost ntpd[9470]: 0.0.0.0 c614 04 freq_mode
4. 讓系統在開機時自動啟用 ntpd daemon
上面步驟做的事情在重開機之後就無效了,因此要用 systemctl enable ntpd 將 daemon 啟用,
或是也可以用 chkconfig ntpd on~
root@localhost ~ # systemctl is-enabled ntpd disabled root@localhost ~ # systemctl enable ntpd ln -s '/usr/lib/systemd/system/ntpd.service' '/etc/systemd/system/multi-user.target.wants/ntpd.service' root@localhost ~ # systemctl is-enabled ntpd enabled
上面都設定好之後,系統時間就都會是正確的囉~^^