楼主在这里用chrony，一般redhat7和CentOS7默认已安装chrony
yum install chrony
修改配置文件，添加时间服务器
vi /etc/chrony.conf
# server 0.asia.pool.ntp.org iburst
# server 1.asia.pool.ntp.org iburst
# server 2.asia.pool.ntp.org iburst
# server 3.asia.pool.ntp.org iburst
server 192.168.101.1 #本地物理机
server ntp1.aliyun.com
server time1.aliyun.com
启动服务
systemctl start chronyd
验证
[root@ceph-deploy ~]# chronyc sources -v //查看时间同步源
210 Number of sources = 3
.-- 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
===============================================================================
^? gateway 0 6 0 - +0ns[ +0ns] +/- 0ns
^? 120.25.115.20 2 6 3 5 -2442us[-2442us] +/- 6122us
^? 203.107.6.88 2 6 3 5 -2272us[-2272us] +/- 25ms
[root@ceph-deploy ~]# ss -tulp | grep chronyd // 查看时间同步源状态
udp UNCONN 0 0 127.0.0.1:323 *:* users:(("chronyd",pid=10826,fd=1))
udp UNCONN 0 0 ::1:323 :::* users:(("chronyd",pid=10826,fd=2))
一切看起来很正常，但是一date就发现慢了一天，timedatectl查看一下时区，原来是美国东部时间，也就是时区错了
[root@ceph-deploy ~]# date
Wed Jul 18 22:25:04 EDT 2018
[root@ceph-deploy ~]# timedatectl
Local time: Wed 2018-07-18 22:26:52 EDT
Universal time: Thu 2018-07-19 02:26:52 UTC
RTC time: Thu 2018-07-19 02:26:32
Time zone: America/New_York (EDT, -0400)
NTP enabled: yes
NTP synchronized: yes
RTC in local TZ: no
DST active: yes
Last DST change: DST began at
Sun 2018-03-11 01:59:59 EST
Sun 2018-03-11 03:00:00 EDT
Next DST change: DST ends (the clock jumps one hour backwards) at
Sun 2018-11-04 01:59:59 EDT
Sun 2018-11-04 01:00:00 EST
复制响应的时区文件到/etc/localtime，最后才把时间调整过来，出现这种情况一般是安装系统的时候没选对时区，默认就是美国东部时间
cp /usr/share/zoneinfo/$主时区/$次时区 /etc/localtime
[root@ceph-deploy ~]# cd /usr/share/zoneinfo/
[root@ceph-deploy zoneinfo]# cp Asia/Shanghai /etc/localtime
cp: overwrite ‘/etc/localtime’? y
[root@ceph-deploy zoneinfo]# date
Thu Jul 19 10:31:10 CST 2018