Linux - 問題 & 解決

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

問題：

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：依賴性衝突
解決方法：在語句後面添加 --nodeps

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

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

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

問題：

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安裝了舊版本的GPG keys
解決方法：在語句後面添加 --force --nodeps

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

參考文章鏈接：https://blog.csdn.net/sunforraining/article/details/79836998

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

問題：

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

原因：未安裝libaio
解決方案：安裝libaio

yum install -y libaio

參考文章鏈接：https://blog.csdn.net/eagle89/article/details/78411184

4 使用RPM包安裝軟件

參考文章鏈接：https://www.cnblogs.com/gmlkl/p/9354254.html

5 MySQL - 虛擬機NAT模式下 Host ‘192.168.x.1’ is not allowed to connect to this MySQL server 問題

問題：

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

原因：中間多了NAT的網絡地址，需要添加相應的權限
解決方案：
（1）在虛擬機相應機器上，登錄mysql

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

（2）授予相應權限

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

（3）刷新privileges

mysql> flush privileges;

參考文章連接：https://blog.csdn.net/weixin_42350212/article/details/80635634

6 ntpdate -u ntp1.aliyun.com更新時間時失敗 & 重啓後更新時間失敗

問題1：

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

原因：

安裝的是minimal版本的Linux，ntp命令需要單獨的安裝

解決方案：

yum install -y ntp

問題2：

重啓機器後發現修改的時間未有效

原因：

更新時修改的是系統時間，而重啓後，系統時間會更新爲機器硬件時間，因此修改時間時需要將修改的系統時間同步到機器的額硬件時間

解決方法：
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 ~]$