Linux - 问题 & 解决

1 MySQL - rpm -ev mysql-libs-5.1.73-8.el6_8.x86_64

问题：

error: Failed dependencies:
        libmysqlclient.so.16()(64bit) is needed by (installed) postfix-2:2.6.6-8.el6.x86_64
        libmysqlclient.so.16(libmysqlclient_16)(64bit) is needed by (installed) postfix-2:2.6.6-8.el6.x86_64
        mysql-libs is needed by (installed) postfix-2:2.6.6-8.el6.x86_64

原因：依赖性冲突
解决方法：在语句后面添加 --nodeps

rpm -ev mysql-libs-5.1.73-8.el6_8.x86_64 --nodeps

参考文章1链接：https://blog.csdn.net/qq_34872748/article/details/86517639
参考文章2链接：https://www.cnblogs.com/kerrycode/p/4353755.html

2 MySQL - 安装MySQL-client-5.5.47-1.linux2.6.x86_64.rpm

问题：

warning: MySQL-client-5.5.47-1.linux2.6.x86_64.rpm: Header V3 DSA/SHA1 Signature, key ID 5072e1f5: NOKEY
error: Failed dependencies:
        /usr/bin/perl is needed by MySQL-client-5.5.47-1.linux2.6.x86_64

原因：yum安装了旧版本的GPG keys
解决方法：在语句后面添加 --force --nodeps

rpm -ivh MySQL-client-5.5.47-1.linux2.6.x86_64.rpm --force --nodeps

参考文章链接：https://blog.csdn.net/sunforraining/article/details/79836998

3 MySQL - 安装MySQL-server-5.5.47-1.linux2.6.x86_64.rpm

问题：

/usr/sbin/mysqld: error while loading shared libraries: libaio.so.1: cannot open shared object file: No such file or directory

原因：未安装libaio
解决方案：安装libaio

yum install -y libaio

参考文章链接：https://blog.csdn.net/eagle89/article/details/78411184

4 使用RPM包安装软件

参考文章链接：https://www.cnblogs.com/gmlkl/p/9354254.html

5 MySQL - 虚拟机NAT模式下 Host ‘192.168.x.1’ is not allowed to connect to this MySQL server 问题

问题：

Host ‘192.168.137.1’ is not allowed to connect to this MySQL server

原因：中间多了NAT的网络地址，需要添加相应的权限
解决方案：
（1）在虚拟机相应机器上，登录mysql

[root@hadoop01 ~]# mysql -u root -p

（2）授予相应权限

 GRANT ALL PRIVILEGES ON *.* TO 'root'@'192.168.39.1' IDENTIFIED BY '密码' WITH GRANT OPTION

（3）刷新privileges

mysql> flush privileges;

参考文章连接：https://blog.csdn.net/weixin_42350212/article/details/80635634

6 ntpdate -u ntp1.aliyun.com更新时间时失败 & 重启后更新时间失败

问题1：

[hadoop@hadoop105 ~]$ ntpdate -u ntp1.aliyun.com
-bash: ntpdate: command not found

原因：

安装的是minimal版本的Linux，ntp命令需要单独的安装

解决方案：

yum install -y ntp

问题2：

重启机器后发现修改的时间未有效

原因：

更新时修改的是系统时间，而重启后，系统时间会更新为机器硬件时间，因此修改时间时需要将修改的系统时间同步到机器的额硬件时间

解决方法：
root@hadoop02

[root@hadoop02 ~]# ntpdate -u ntp1.aliyun.com
[root@hadoop02 ~]# date
[root@hadoop02 ~]# hwclock --systohc
[root@hadoop02 ~]# hwclock --show

hadoop@hadoop107

[hadoop@hadoop107 ~]$  sudo ntpdate -u ntp1.aliyun.com
[sudo] password for hadoop: 
 8 Sep 10:15:29 ntpdate[1452]: step time server 120.25.115.20 offset -28747.727054 sec
[hadoop@hadoop107 ~]$ date
Sun Sep  8 10:15:32 CST 2019
[hadoop@hadoop107 ~]$ sudo hwclock --systohc
sudo: timestamp too far in the future: Sep  8 18:14:36 2019

We trust you have received the usual lecture from the local System
Administrator. It usually boils down to these three things:

    #1) Respect the privacy of others.
    #2) Think before you type.
    #3) With great power comes great responsibility.

[sudo] password for hadoop: 
[hadoop@hadoop107 ~]$ sudo hwclock --show
Sun 08 Sep 2019 10:15:55 AM CST  -0.954515 seconds
[hadoop@hadoop107 ~]$