centos7离线安装yum centos7离线安装ntp服务

centos7-时间同步NTP安装,以及libopts.so.25问题解决

ntp时间同步服务器同来同步时间

文章目录

• centos7-时间同步NTP安装,以及libopts.so.25问题解决

• 安装

• 依赖包
• 安装步骤

• 使用
• /etc/ntp.conf 配置文件
• 问题
• 如果卸载了服务，查看服务状态，服务还在，请刷新systemctl的缓存

安装

依赖包

ntp服务安装需要三个包：

autogen-libopts-5.18-5.el7.x86_64.rpm

ntpdate-4.2.6p5-25.el7.centos.2.x86_64.rpm

ntp-4.2.6p5-25.el7.centos.2.x86_64.rpm

安装步骤

直接yum安装即可

yum -y install ntp

使用

有两种使用方法

1. 执行命令来同步

ntpdate -u 202.120.2.101

1. 设置为守护进程来同步

1. 修改配置文件

vi /etc/ntp.conf

#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 time7.aliyun.com prefer iburst //添加一个同步服务器设置即可

1. 启动守护程序

systemctl start ntpd //启动
systemctl stop ntpd //停止
systemctl status ntpd //查看服务状态
systemctl enable ntpd //设置开机自启

/etc/ntp.conf 配置文件

# 系统时间与BIOS事件的偏差记录
driftfile /var/lib/ntp/drift 

#restrict 控制相关权限。语法为： restrict IP地址 mask 子网掩码 参数
#其中IP地址也可以是default ，default 就是指所有的IP
#参数有以下几个：
#ignore  ：关闭所有的 NTP 联机服务
#nomodify：客户端不能更改服务端的时间参数，但是客户端可以通过服务端进行网络校时。
#notrust ：客户端除非通过认证，否则该客户端来源将被视为不信任子网
#noquery ：不提供客户端的时间查询：用户端不能使用ntpq，ntpc等命令来查询ntp服务器
#notrap ：不提供trap远端登陆：拒绝为匹配的主机提供模式 6 控制消息陷阱服务。陷阱服务是 ntpdq 控制消息协议的子系统，用于远程事件#日志记录程序。
#nopeer ：用于阻止主机尝试与服务器对等，并允许欺诈性服务器控制时钟
#kod ： 访问违规时发送 KoD 包。
#restrict -6 表示IPV6地址的权限设置

restrict default nomodify notrap nopeer noquery

#确保localhost（这个常用的IP地址用来指Linux服务器本身）有足够权限.使用没有任何限制关键词的语法
restrict 127.0.0.1
restrict ::1

#
restrict 192.168.1.0 mask 255.255.255.0 nomodify notrap

#设定NTP主机来源（其中prefer表示优先主机），192.168.7.49是本地的NTP服务器，所以优先指定从该主机同步时间。
server 0.centos.pool.ntp.org prefer
server 0.centos.pool.ntp.org iburst

#broadcast 192.168.1.255 autokey        # broadcast server
#broadcastclient                        # broadcast client
#broadcast 224.0.1.1 autokey            # multicast server
#multicastclient 224.0.1.1              # multicast client
#manycastserver 239.255.254.254         # manycast server
#manycastclient 239.255.254.254 autokey # manycast client

# Enable public key cryptography.
#crypto

#
includefile /etc/ntp/crypto/pw

# Key file containing the keys and key identifiers used when operating
keys /etc/ntp/keys

# Specify the key identifiers which are trusted.
#trustedkey 4 8 42

# Specify the key identifier to use with the ntpdc utility.
#requestkey 8

# Specify the key identifier to use with the ntpq utility.
#controlkey 8

# Enable writing of statistics records.
#statistics clockstats cryptostats loopstats peerstats

# Disable the monitoring facility to prevent amplification attacks using ntpdc
# monlist command when default restrict does not include the noquery flag. See
# CVE-2013-5211 for more details.
# Note: Monitoring will not be disabled with the limited restriction flag.
disable monitor

问题

1. 在启动ntpd后查看ntpd服务的状态，会发现，ntpd启动失败，报错如下

# systemctl status ntpd
ntpd.service - Network Time Service
   Loaded: loaded (/usr/lib/systemd/system/ntpd.service; disabled; vendor preset: disabled)
   Active: failed (Result: exit-code) since Mon 2022-04-18 09:19:50 CST; 6min ago

Apr 18 09:19:50 172-16-23-219 systemd[1]: Starting Network Time Service...
Apr 18 09:19:50 172-16-23-219 ntpd[2778]: /usr/sbin/ntpd: error while loading shared libraries: libopts.so.25: can...ctory
Apr 18 09:19:50 172-16-23-219 systemd[1]: ntpd.service: control process exited, code=exited status=127
Apr 18 09:19:50 172-16-23-219 systemd[1]: Failed to start Network Time Service.
Apr 18 09:19:50 172-16-23-219 systemd[1]: Unit ntpd.service entered failed state.
Apr 18 09:19:50 172-16-23-219 systemd[1]: ntpd.service failed.
Hint: Some lines were ellipsized, use -l to show in full.

报错 libopts.so.25 这个文件的问题，可能是缺少这个文件，解决方法就是重装 autogen-libopts

1. 卸载 ntp以及ntpdate

yum remove ntp
yum remove ntpdate
# 如果执行 systemctl status ntpd 后还是提示状态是失败的，则需要刷新一下systemctl 的缓存
# systemctl daemon-reload
# systemctl reset-failed

1. 卸载重装 autogen-libopts

yum  remove autogen-libopts
yum install -y autogen-libopts

1. 重新安装 ntp以及重新设置配置

yum install -y ntp
vi /etc/ntp.conf

1. 启动并设置为开机启动，查看状态就行了

systemctl start ntpd //启动
systemctl stop ntpd //停止
systemctl status ntpd //查看服务状态
systemctl enable ntpd //设置开机自启

1. 报错没有用户 ntp或者没有用户组 ntp

1. 报错

1. 无用户/用户组

# systemctl status ntpd
ntpd.service - Network Time Service
   Loaded: loaded (/usr/lib/systemd/system/ntpd.service; disabled; vendor preset: disabled)
   Active: failed (Result: exit-code) since Mon 2022-04-18 09:27:38 CST; 2s ago
  Process: 16586 ExecStart=/usr/sbin/ntpd -u ntp:ntp $OPTIONS (code=exited, status=0/SUCCESS)
 Main PID: 16587 (code=exited, status=255)

Apr 18 09:27:38 172-16-23-219 ntpd[16587]: Listen normally on 14 cali503f030177a fe80::ecee:eeff:feee:eeee UDP 123
Apr 18 09:27:38 172-16-23-219 ntpd[16587]: Listen normally on 15 eth0 fe80::f881:3eff:fed1:f300 UDP 123
Apr 18 09:27:38 172-16-23-219 ntpd[16587]: Listening on routing socket on fd #32 for interface updates
Apr 18 09:27:38 172-16-23-219 ntpd[16587]: 0.0.0.0 c016 06 restart
Apr 18 09:27:38 172-16-23-219 ntpd[16587]: 0.0.0.0 c012 02 freq_set kernel 0.000 PPM
Apr 18 09:27:38 172-16-23-219 ntpd[16587]: 0.0.0.0 c011 01 freq_not_set
Apr 18 09:27:38 172-16-23-219 ntpd[16587]: Cannot find user `ntp'
Apr 18 09:27:38 172-16-23-219 systemd[1]: ntpd.service: main process exited, code=exited, status=255/n/a
Apr 18 09:27:38 172-16-23-219 systemd[1]: Unit ntpd.service entered failed state.
Apr 18 09:27:38 172-16-23-219 systemd[1]: ntpd.service failed.


## 或者是：
# systemctl status ntpd
ntpd.service - Network Time Service
   Loaded: loaded (/usr/lib/systemd/system/ntpd.service; disabled; vendor preset: disabled)
   Active: inactive (dead)

Apr 18 09:40:32 172-16-23-219 ntpd[5295]: Listen normally on 12 caliae05d320986 fe80::ecee:eeff:feee:eeee UDP 123
Apr 18 09:40:32 172-16-23-219 ntpd[5295]: Listen normally on 13 calib3c53cc58f8 fe80::ecee:eeff:feee:eeee UDP 123
Apr 18 09:40:32 172-16-23-219 ntpd[5295]: Listen normally on 14 cali503f030177a fe80::ecee:eeff:feee:eeee UDP 123
Apr 18 09:40:32 172-16-23-219 ntpd[5295]: Listen normally on 15 eth0 fe80::f881:3eff:fed1:f300 UDP 123
Apr 18 09:40:32 172-16-23-219 ntpd[5295]: Listening on routing socket on fd #32 for interface updates
Apr 18 09:40:32 172-16-23-219 ntpd[5295]: 0.0.0.0 c016 06 restart
Apr 18 09:40:32 172-16-23-219 ntpd[5295]: 0.0.0.0 c012 02 freq_set kernel 0.000 PPM
Apr 18 09:40:32 172-16-23-219 ntpd[5295]: 0.0.0.0 c011 01 freq_not_set
Apr 18 09:40:32 172-16-23-219 ntpd[5295]: Cannot find group `ntp'
Apr 18 09:40:32 172-16-23-219 systemd[1]: Started Network Time Service.

1. 错误原因

1. 卸载重装autogen-libopts前没把ntp卸载掉
2. 卸载ntp没卸载干净，没把ntpdate卸载干净

2. 解决方法

1. 找一个成功安装ntp的服务器，对比/etc/passwd 以及/etc/group文件，将ntp相关的用户以及用户组，copy到错误的机器对应文件中

1. /etc/passwd:

ntp:x:38:38::/etc/ntp:/sbin/nologin

1. /etc/group

ntp:x:38:

1. 重启ntp

systemctl restart ntpd

1. 完全卸载ntp在重装

yum remove ntp
yum remove ntpdate
yum install -y ntp
vi /etc/ntp.conf
systemctl start ntpd //启动
systemctl stop ntpd //停止
systemctl status ntpd //查看服务状态
systemctl enable ntpd //设置开机自启

如果卸载了服务，查看服务状态，服务还在，请刷新systemctl的缓存

systemctl daemon-reload
systemctl reset-failed