# Customized NTP Server * 下載ntp service ```bash= apt-get install ntp ``` * 下載完ntp service後需將/etc/ntp.conf裡預設的上層NTP Server註解掉，否則預設NTP會每64秒去sync上層NTP server，如果系統時間與上層NTP server相差太多，ntp service會報錯。 ```bash= vi /etc/ntp.conf ``` ```vi= # Specify one or more NTP servers. # Use servers from the NTP Pool Project. Approved by Ubuntu Technical Board # on 2011-02-08 (LP: #104525). See http://www.pool.ntp.org/join.html for # more information. pool 0.ubuntu.pool.ntp.org iburst pool 1.ubuntu.pool.ntp.org iburst pool 2.ubuntu.pool.ntp.org iburst pool 3.ubuntu.pool.ntp.org iburst # Use Ubuntu's ntp server as a fallback. pool ntp.ubuntu.com ``` 將以上6~9行、12行註解 ```vi= # Specify one or more NTP servers. # Use servers from the NTP Pool Project. Approved by Ubuntu Technical Board # on 2011-02-08 (LP: #104525). See http://www.pool.ntp.org/join.html for # more information. #pool 0.ubuntu.pool.ntp.org iburst #pool 1.ubuntu.pool.ntp.org iburst #pool 2.ubuntu.pool.ntp.org iburst #pool 3.ubuntu.pool.ntp.org iburst # Use Ubuntu's ntp server as a fallback. #pool ntp.ubuntu.com ``` > 錯誤訊息example: > ntp.service: Main process exited, code=exited, status=255/EXCEPTION ntp.service: Failed with result 'exit-code'. * 註解後重啟ntp service ```bash= systemctl restart ntp system ntp status # 查看ntp sevice狀態 date +"%Y-%m-%d %H:%M:%S" # 更改系統時間 ``` * 重啟完後再更改時間就不會受到上層NTP server影響 可在另外一台PC上用ntpdate測試sync到customized NTP server ```bash= apt-get install ntpdate ntpdate {customized_ntp_ip} ntpdate -d {customized_ntp_ip} # 依debug模式測試ntpdate ``` --- 參考資料: 1. [Setup NTP](https://linuxconfig.org/stay-time-synchronized-with-internet-time-server) 2. [NTP service error message解釋](https://github.com/coreos/bugs/issues/61) 3. [ntpdate command](https://linux.die.net/man/8/ntpdate)