chrony를 통한 시간동기화

[AS-IS] # Use public servers from the pool.ntp.org project. # Please consider joining the pool (http://www.pool.ntp.org/join.html). server 0.centos.pool.ntp.org iburst server 1.centos.pool.ntp.org iburst server 2.centos.pool.ntp.org iburst server 3.centos.pool.ntp.org iburst [TO-BE] # Use public servers from the pool.ntp.org project. # Please consider joining the pool (http://www.pool.ntp.org/join.html). #server 0.centos.pool.ntp.org iburst #server 1.centos.pool.ntp.org iburst #server 2.centos.pool.ntp.org iburst #server 3.centos.pool.ntp.org iburst server 10.64.237.49 iburst

[root@svr ~]# systemctl enable chronyd

[root@svr ~]# systemctl status chronyd; systemctl restart chronyd; systemctl status chronyd

[root@svr ~]# timedatectl Local time: Tue 2021-11-09 10:16:13 KST Universal time: Tue 2021-11-09 01:16:13 UTC RTC time: Tue 2021-11-09 01:16:13 Time zone: Asia/Seoul (KST, +0900) NTP enabled: yes <==== NTP 활성화 여부 확인 NTP synchronized: yes <==== NTP 동기화 여부 확인 RTC in local TZ: no DST active: n/a

[root@svr ~]# chronyc sources -v 210 Number of sources = 1 .-- Source mode '^' = server, '=' = peer, '#' = local clock. / .- Source state '*' = current synced, '+' = combined , '-' = not combined, | / '?' = unreachable, 'x' = time may be in error, '~' = time too variable. || .- xxxx [ yyyy ] +/- zzzz || Reachability register (octal) -. | xxxx = adjusted offset, || Log2(Polling interval) --. | | yyyy = measured offset, || \ | | zzzz = estimated error. || | | \ MS Name/IP address Stratum Poll Reach LastRx Last sample =============================================================================== ^* 10.64.237.49 3 6 37 29 +129ns[ +161us] +/- 4722us <==== 만약 마스터 노드와 통신이 되지 않는다면 0으로 표기됨

[root@svr ~]# chronyc -a makestep; hwclock -w