立即校時

1. 查詢目前時間

   [root@kvm8 ~]# date
   Wed Nov  2 02:05:08 PM CST 2022
   

2. 將時間設定成不是今天的日期 (2021-11-11)。

   [root@kvm8 ~]# date -s 2021-11-11
   Thu Nov 11 12:00:00 AM CST 2021
   

3. 不關閉 chronyd 服務，使用 -Q 選項，可以查看時間誤差，但不會真的校時。

   [root@kvm8 ~]# chronyd -Q "pool deyu.wang iburst"
   2021-11-10T16:00:17Z chronyd version 4.1 starting (+CMDMON +NTP +REFCLOCK
   +RTC +PRIVDROP +SCFILTER +SIGND +ASYNCDNS +NTS +SECHASH +IPV6 +DEBUG)
   2021-11-10T16:00:17Z Disabled control of system clock
   2021-11-10T16:00:21Z System clock wrong by 30809113.195522 seconds (ignored)
   2021-11-10T16:00:21Z chronyd exiting
   

4. 要用 chronyd 立即校時，必須先關閉 chronyd 服務。

   [root@kvm8 ~]# systemctl stop chronyd.service
   

5. chronyd 立即校時，校正 30809113.195512 秒。

   [root@kvm8 ~]# chronyd -q "pool deyu.wang iburst"
   2021-11-10T16:01:04Z chronyd version 4.1 starting (+CMDMON +NTP +REFCLOCK
   +RTC +PRIVDROP +SCFILTER +SIGND +ASYNCDNS +NTS +SECHASH +IPV6 +DEBUG)
   2021-11-10T16:01:04Z Initial frequency -11.769 ppm
   2021-11-10T16:01:08Z System clock wrong by 30809113.195512 seconds (step)
   2022-11-02T06:06:21Z chronyd exiting
   

6. 再查時間，校時成功。

   [root@kvm8 ~]# date
   Wed Nov  2 02:06:25 PM CST 2022
   

7. 恢復啟動 chronyd 服務

   [root@kvm8 ~]# systemctl start chronyd.service