# 校時與時區設定 #### Tutorials - [How to Sync Linux Time With NTP Server - Make Tech Easier](https://www.maketecheasier.com/sync-linux-time-with-ntp-server/) #### Chrony Built-in on CentOS/RedHat - [CHAPTER 18. CONFIGURING NTP USING THE CHRONY SUITE](https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/system_administrators_guide/ch-configuring_ntp_using_the_chrony_suite) - [CentOS / RHEL 7 : Configuring NTP using chrony](https://www.thegeekdiary.com/centos-rhel-7-configuring-ntp-using-chrony/) - [How do I check Linux system’s current NTP configuration](https://www.nixcraft.com/t/how-do-i-check-linux-systems-current-ntp-configuration/3519) Install ``` yum install chrony ``` Config: /etc/chrony.conf ``` # NTP Public Servers for Taiwan server tw.pool.ntp.org server time.stdtime.gov.tw server clock.stdtime.gov.tw server jp.pool.ntp.org # Allow NTP client access from local network. #allow 192.168.0.0/16 ``` Starting ``` systemctl start chronyd ``` Verify ``` [root@localhost ~]# chronyc tracking Reference ID : 7A75FDF6 (static.home.twn.sciuridae.cloud) Stratum : 3 Ref time (UTC) : Sun Aug 16 03:35:36 2020 System time : 0.000073180 seconds slow of NTP time Last offset : -0.001259724 seconds RMS offset : 0.001259724 seconds Frequency : 21.057 ppm slow Residual freq : -0.000 ppm Skew : 28.166 ppm Root delay : 0.032856792 seconds Root dispersion : 0.002069760 seconds Update interval : 64.3 seconds Leap status : Normal <=== [root@tpemimtst99 ~]# timedatectl Local time: Tue 2021-05-25 09:09:09 CST Universal time: Tue 2021-05-25 01:09:09 UTC RTC time: Tue 2021-05-25 01:09:09 Time zone: Asia/Taipei (CST, +0800) System clock synchronized: yes <=== NTP service: active RTC in local TZ: no [root@tpemimtst99 ~]# chronyc sources 210 Number of sources = 1 MS Name/IP address Stratum Poll Reach LastRx Last sample =============================================================================== ^* 192.168.21.86 3 10 377 754 +1543ns[+4123ns] +/- 63ms ``` #### systemd-timesyncd Build-in on Ubuntu - [Control your computer time and date with systemd](https://opensource.com/article/20/6/time-date-systemd) Installation ```bash sudo apt install systemd-timesyncd ``` The configuration file for systemd-timesyncd is `/etc/systemd/timesyncd.conf`. ``` [Time] #NTP= #FallbackNTP=0.debian.pool.ntp.org 1.debian.pool.ntp.org 2.debian.pool.ntp.org 3.debian.pool.ntp.org #RootDistanceMaxSec=5 #PollIntervalMinSec=32 #PollIntervalMaxSec=2048 ``` Specify the time server as follows ``` NTP= ``` Start timesync ```shell systemctl enable systemd-timesyncd.service systemctl start systemd-timesyncd.service ``` timedatectl ```shell # See the information of the datetime sudo timedatectl Local time: Mon 2021-11-01 14:37:09 UTC Universal time: Mon 2021-11-01 14:37:09 UTC RTC time: Mon 2021-11-01 14:37:10 Time zone: UTC (UTC, +0000) System clock synchronized: yes NTP service: active <==== RTC in local TZ: no # List timezones supported sudo timedatectl list-timezones # Change the system’s timezone sudo timedatectl set-timezone Asia/Taipei # Check the status sudo timedatectl timesync-status Server: 91.189.91.157 (ntp.ubuntu.com) Poll interval: 17min 4s (min: 32s; max 34min 8s) Leap: normal Version: 4 Stratum: 2 Reference: 11FD227B Precision: 1us (-24) Root distance: 72.295ms (max: 5s) Offset: +5.311ms Delay: 67.290ms Jitter: 2.211ms Packet count: 6 Frequency: +17.421ppm ``` #### ntpd Install ```shell # Ubuntu sudo apt install ntp ``` `vi /etc/ntp.conf` ``` #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 # Added the local time server server 192.168.21.86 prefer iburst ``` Restart the ntpd ``` # Ubuntu 16.04 systemctl stop ntp systemctl start ntp # Check the timeserver ntpq -p remote refid st t when poll reach delay offset jitter ============================================================================== 0.ubuntu.pool.n .POOL. 16 p - 64 0 0.000 0.000 0.000 1.ubuntu.pool.n .POOL. 16 p - 64 0 0.000 0.000 0.000 2.ubuntu.pool.n .POOL. 16 p - 64 0 0.000 0.000 0.000 3.ubuntu.pool.n .POOL. 16 p - 64 0 0.000 0.000 0.000 ntp.ubuntu.com .POOL. 16 p - 64 0 0.000 0.000 0.000 +eterna.binary.n 216.218.192.202 2 u 32 64 3 45.986 -0.081 0.021 +pacific.latt.ne 193.187.181.6 3 u 30 64 3 8.205 1.151 0.026 -mis.wci.com 216.218.192.202 2 u 32 64 3 37.928 4.692 0.176 -europa.ellipse. 209.180.247.49 2 u 31 64 3 51.792 4.175 0.027 #38.229.56.9 172.16.21.35 2 u 30 64 3 68.917 -4.451 0.190 #time.richiemcin 97.183.206.88 2 u 29 64 3 69.281 -3.073 0.248 *t1.time.gq1.yah 208.71.46.33 2 u 30 64 3 31.630 -0.081 0.011 -lofn.fancube.co 220.181.254.66 2 u 30 64 3 37.871 -1.088 0.009 #2606:6680:8:1:: 107.46.198.112 2 u 26 64 3 198.284 66.201 0.061 -titan.crash-ove 129.7.1.66 2 u 30 64 3 32.708 -1.474 0.200 -2620:1d5:100:43 47.187.174.51 2 u 29 64 3 70.418 0.592 0.197 2001:67c:1560:8 17.253.34.123 2 u 32 64 3 133.490 -2.818 0.030 #38.229.57.9 172.16.21.35 2 u 30 64 3 177.896 4.081 6.291 #ntp2i.versadns. 217.180.209.214 2 u 28 64 3 62.795 -2.897 0.017 -104.194.8.227 192.12.19.20 2 u 25 64 3 0.979 -0.737 0.029 -pacific.latt.ne 193.187.181.6 3 u 26 64 3 8.770 1.212 0.050 2001:67c:1560:8 17.253.34.123 2 u 33 64 3 133.602 -2.792 0.007 ``` #### Change Timezone ##### RedHat 7+ ```bash timedatectl timedatectl list-timezones timedatectl set-timezone Asia/Taipei ``` ##### CentOS 6 ```bash # List of timezone ls /usr/share/zoneinfo # Check the current timezone set cat /etc/sysconfig/clock ``` Edit: /etc/sysconfig/clock ``` ZONE="Asia/Taipei" UTC=true ``` Localtime ```bash mv /etc/localtime /etc/localtime.bak ln -sf /usr/share/zoneinfo/Asia/Taipei /etc/localtime ``` ##### Debian 13 ```bash sudo timedatectl set-timezone Asia/Taipei ``` #### Manually Set the date-time ```bash date -s "6 April 2023 15:11:00" ```