NTP常见日志分析
chrony日志示例：
[root@localhost ~]# journalctl -u chronyd --no-pager
-- Logs begin at Tue 2025-07-22 00:58:03 CST, end at Tue 2025-08-12 17:08:27 CST. --
Jul 22 01:00:10 localhost.localdomain chronyd[3817]: Backward time jump detected!
Jul 22 01:00:10 localhost.localdomain chronyd[3817]: Can't synchronise: no selectable sources
Jul 22 01:02:19 localhost.localdomain chronyd[3817]: Selected source 117.80.231.60 (2.centos.pool.ntp.org)
Jul 22 01:02:19 localhost.localdomain chronyd[3817]: System clock wrong by 56863.012789 seconds
Jul 22 01:03:26 localhost.localdomain chronyd[3817]: Selected source 202.118.1.81 (2.centos.pool.ntp.org)
Jul 22 00:59:59 localhost.localdomain chronyd[3817]: Backward time jump detected!
Jul 22 00:59:59 localhost.localdomain chronyd[3817]: Can't synchronise: no selectable sources
Jul 22 00:59:48 localhost.localdomain chronyd[3817]: Backward time jump detected!
Jul 22 01:01:58 localhost.localdomain chronyd[3817]: Selected source 202.118.1.81 (2.centos.pool.ntp.org)
Jul 22 01:01:58 localhost.localdomain chronyd[3817]: System clock wrong by 57259.198768 seconds
Jul 22 01:03:02 localhost.localdomain chronyd[3817]: Selected source 117.80.231.60 (2.centos.pool.ntp.org)
Jul 22 01:04:07 localhost.localdomain chronyd[3817]: Selected source 202.118.1.81 (2.centos.pool.ntp.org)
Jul 22 02:59:43 localhost.localdomain chronyd[3817]: Forward time jump detected!
Jul 22 02:59:43 localhost.localdomain chronyd[3817]: Can't synchronise: no selectable sources
Jul 22 03:00:07 localhost.localdomain chronyd[3817]: Backward time jump detected!
Jul 22 02:59:39 localhost.localdomain chronyd[3817]: Backward time jump detected!
Jul 22 02:59:50 localhost.localdomain chronyd[3817]: Backward time jump detected!
Jul 22 02:59:45 localhost.localdomain chronyd[3817]: Backward time jump detected!
Jul 22 03:01:57 localhost.localdomain chronyd[3817]: Selected source 202.118.1.81 (2.centos.pool.ntp.org)
Jul 22 03:01:57 localhost.localdomain chronyd[3817]: System clock wrong by 50693.197028 seconds
Jul 22 01:00:00 localhost.localdomain chronyd[3817]: Backward time jump detected!
Jul 22 01:00:00 localhost.localdomain chronyd[3817]: Can't synchronise: no selectable sources
Jul 22 00:59:46 localhost.localdomain chronyd[3817]: Backward time jump detected!
Jul 22 00:58:03 localhost.localdomain chronyd[3817]: Backward time jump detected!
Jul 22 01:00:13 localhost.localdomain chronyd[3817]: Selected source 116.203.151.74 (2.centos.pool.ntp.org)
Jul 22 01:00:13 localhost.localdomain chronyd[3817]: System clock wrong by 58385.540895 seconds
Jul 24 13:41:35 localhost.localdomain chronyd[3817]: Forward time jump detected!
Jul 24 13:41:35 localhost.localdomain chronyd[3817]: Can't synchronise: no selectable sources
Jul 24 13:43:44 localhost.localdomain chronyd[3817]: Selected source 117.80.231.60 (2.centos.pool.ntp.org)
Jul 24 13:43:44 localhost.localdomain chronyd[3817]: System clock wrong by -6.579411 seconds
Jul 24 13:43:53 localhost.localdomain chronyd[3817]: Selected source 193.182.111.12 (2.centos.pool.ntp.org)
Jul 24 13:44:49 localhost.localdomain chronyd[3817]: Selected source 117.80.231.60 (2.centos.pool.ntp.org)
Jul 24 13:44:49 localhost.localdomain chronyd[3817]: Source 117.80.231.60 replaced with 193.182.111.14 (2.centos.pool.ntp.org)
Jul 24 13:44:52 localhost.localdomain chronyd[3817]: Selected source 202.118.1.81 (2.centos.pool.ntp.org)
Jul 24 14:32:19 localhost.localdomain chronyd[3817]: Source 202.118.1.81 replaced with 119.28.206.193 (2.centos.pool.ntp.org)
Jul 24 14:32:28 localhost.localdomain chronyd[3817]: Selected source 116.203.151.74 (2.centos.pool.ntp.org)
Jul 30 15:03:34 localhost.localdomain chronyd[3817]: Forward time jump detected!
Jul 30 15:03:34 localhost.localdomain chronyd[3817]: Can't synchronise: no selectable sources
Jul 30 15:06:49 localhost.localdomain chronyd[3817]: Selected source 193.182.111.12 (2.centos.pool.ntp.org)
Jul 30 15:07:53 localhost.localdomain chronyd[3817]: Selected source 119.28.206.193 (2.centos.pool.ntp.org)
Jul 30 15:07:54 localhost.localdomain chronyd[3817]: Source 116.203.151.74 replaced with 193.182.111.141 (2.centos.pool.ntp.org)
Jul 31 13:57:46 localhost.localdomain chronyd[3817]: Forward time jump detected!
Jul 31 13:57:46 localhost.localdomain chronyd[3817]: Can't synchronise: no selectable sources
Jul 31 14:01:01 localhost.localdomain chronyd[3817]: Selected source 193.182.111.141 (2.centos.pool.ntp.org)
Jul 31 14:02:06 localhost.localdomain chronyd[3817]: Selected source 119.28.206.193 (2.centos.pool.ntp.org)
Jul 31 14:02:08 localhost.localdomain chronyd[3817]: Source 193.182.111.12 replaced with 108.59.2.24 (2.centos.pool.ntp.org)
Aug 01 09:51:21 localhost.localdomain chronyd[3817]: Forward time jump detected!
Aug 01 09:51:21 localhost.localdomain chronyd[3817]: Can't synchronise: no selectable sources
Aug 01 09:54:35 localhost.localdomain chronyd[3817]: Selected source 193.182.111.141 (2.centos.pool.ntp.org)
Aug 01 09:55:40 localhost.localdomain chronyd[3817]: Selected source 119.28.206.193 (2.centos.pool.ntp.org)
Aug 01 09:55:41 localhost.localdomain chronyd[3817]: Source 193.182.111.141 replaced with 210.28.130.4 (2.centos.pool.ntp.org)
Aug 01 10:03:14 localhost.localdomain chronyd[3817]: Selected source 210.28.130.4 (2.centos.pool.ntp.org)
Aug 01 10:29:06 localhost.localdomain chronyd[3817]: Can't synchronise: no selectable sources
Aug 01 16:25:48 localhost.localdomain chronyd[3817]: Forward time jump detected!
Aug 01 16:34:24 localhost.localdomain chronyd[3817]: Selected source 210.28.130.4 (2.centos.pool.ntp.org)
Aug 12 09:07:43 localhost.localdomain chronyd[3817]: Forward time jump detected!
Aug