有些版本的操作系统在镜像里已不包含ntp包了，linux7 可以使用chrony来代替ntp。

chrony服务端和客户单的配置有很多blog有说明，这里只描述下检测是否成功

1.第一种方法

直接对比ntp时间服务器和客户端服务器的时间。这个是明显的、直观的

2.第二种方法

如果配置多台client可以比较相互之间是否有差异，不过这个有一定概率性，除非clinet数量比较多

3.第三种方法

通过命令
chronyc sources -v

3.1不通的情况

# chronyc sources -v
210 Number of sources = 2

  .-- 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               
===============================================================================
^? 192.168.11.253                  0  10     0     -     +0ns[   +0ns] +/-    0ns
^? 192.168.11.252                  9  10     0    5d   -108us[ -129us] +/-   11ms

3.2通的情况

#chronyc sources -v
210 Number of sources = 2

  .-- 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               
===============================================================================
^* 192.168.11.252                  9   8   377    74   -165us[ -193us] +/-   10ms
^? 192.168.11.253                  0  10     0     -     +0ns[   +0ns] +/-    0ns

注意斜体部分中加粗的部分，3.1的？表示不通，3.2*表示通

第四种方法

根据命令反馈
4.1成功

Mar 09 17:09:17 zgbffile02 systemd[1]: Starting NTP client/server...
Mar 09 17:09:17 zgbffile02 chronyd[1461]: chronyd version 3.2 starting (+CMDMON +NTP +REFCLOCK +RTC +PRIVDROP +SCFILTER +SECHASH +SIGND +ASYNCDNS +IPV6 +DEBUG)
Mar 09 17:09:17 zgbffile02 chronyd[1461]: Frequency -123.732 +/- 0.043 ppm read from /var/lib/chrony/drift
Mar 09 17:09:17 zgbffile02 systemd[1]: Started NTP client/server.
Mar 09 17:16:04 zgbffile02 chronyd[1461]: Selected source 192.168.11.253
4.2成功

Mar 11 09:43:57 zgbfbak01 systemd[1]: Starting NTP client/server...
Mar 11 09:43:57 zgbfbak01 chronyd[142049]: chronyd version 3.2 starting (+CMDMON +NTP +REFCLOCK +RTC +PRIVDROP +SCFILTER +SECHASH +SIGND +ASYNCDNS +IPV6 +DEBUG)
Mar 11 09:43:57 zgbfbak01 chronyd[142049]: Frequency 0.000 +/- 1000000.000 ppm read from /var/lib/chrony/drift
Mar 11 09:43:57 zgbfbak01 systemd[1]: Started NTP client/server.
Mar 11 09:44:02 zgbfbak01 chronyd[142049]: Selected source 192.168.11.253
Mar 11 09:44:02 zgbfbak01 chronyd[142049]: System clock wrong by 50.609568 seconds, adjustment started
Mar 11 09:44:52 zgbfbak01 chronyd[142049]: System clock was stepped by 50.609568 seconds 

4.3不成功

Mar 04 15:48:31 zgbfbak02 systemd[1]: Starting NTP client/server...
Mar 04 15:48:31 zgbfbak02 chronyd[108810]: chronyd version 3.2 starting (+CMDMON +NTP +REFCLOCK +RTC +PRIVDROP +SCFILTER +SECHASH +SIGND +ASYNCDNS +IPV6 +DEBUG)
Mar 04 15:48:31 zgbfbak02 systemd[1]: Started NTP client/server.
tips :第一种是已经同步，已经选择了时间服务器的源;第二种是发现与时间服务器不同步，开始调整;第三种情况只是启动了时间服务，并未与时间服务器交互。
查看是否能ping通时间服务器，如果ping能的话systemctl restart chronyd.service