一、ssh登入阿里雲伺服器，檢視mysql的安裝狀態。

[email protected]:~# sudo netstat -tap | grep mysql

tcp        0      0 localhost:mysql         *:*                     LISTEN      24688/mysqld  

以上表示，當前系統已經安裝了mysql。

二、因為種種原因，我需要解除安裝mysql。

1、第一步： sudo apt-get remove mysql-server.

[email protected]:~# sudo apt-get remove mysql-server

Reading package lists... Done

Building dependency tree       

Reading state information... Done

The following packages were automatically installed and are no longer required:

  libcgi-fast-perl libcgi-pm-perl libencode-locale-perl libevent-core-2.0-5 libfcgi-perl libhtml-parser-perl libhtml-tagset-perl libhtml-template-perl libhttp-date-perl

  libhttp-message-perl libio-html-perl liblwp-mediatypes-perl liburi-perl mysql-server-5.7 mysql-server-core-5.7

Use 'sudo apt autoremove' to remove them.

The following packages will be REMOVED:

  mysql-server

0 upgraded, 0 newly installed, 1 to remove and 48 not upgraded.

After this operation, 175 kB disk space will be freed.

Do you want to continue? [Y/n] y

(Reading database ... 100504 files and directories currently installed.)

Removing mysql-server (5.7.17-0ubuntu0.16.04.2) ...

[email protected]:~# sudo apt-get autoremove mysql-server

Reading package lists... Done

Building dependency tree       

Reading state information... Done

Package 'mysql-server' is not installed, so not removed

The following packages will be REMOVED:

  libcgi-fast-perl libcgi-pm-perl libencode-locale-perl libevent-core-2.0-5 libfcgi-perl libhtml-parser-perl libhtml-tagset-perl libhtml-template-perl libhttp-date-perl

  libhttp-message-perl libio-html-perl liblwp-mediatypes-perl liburi-perl mysql-server-5.7 mysql-server-core-5.7

0 upgraded, 0 newly installed, 15 to remove and 48 not upgraded.

After this operation, 96.3 MB disk space will be freed.

Do you want to continue? [Y/n] y

(Reading database ... 100500 files and directories currently installed.)

Removing libcgi-fast-perl (1:2.10-1) ...

Removing libhtml-template-perl (2.95-2) ...

Removing libcgi-pm-perl (4.26-1) ...

Removing libhttp-message-perl (6.11-1) ...

Removing libencode-locale-perl (1.05-1) ...

Removing mysql-server-5.7 (5.7.17-0ubuntu0.16.04.2) ...

update-alternatives: using /etc/mysql/my.cnf.fallback to provide /etc/mysql/my.cnf (my.cnf) in auto mode

Removing libevent-core-2.0-5:amd64 (2.0.21-stable-2ubuntu0.16.04.1) ...

Removing libfcgi-perl (0.77-1build1) ...

Removing libhtml-parser-perl (3.72-1) ...

Removing libhtml-tagset-perl (3.20-2) ...

Removing libhttp-date-perl (6.02-1) ...

Removing libio-html-perl (1.001-1) ...

Removing liblwp-mediatypes-perl (6.02-1) ...

Removing liburi-perl (1.71-1) ...

Removing mysql-server-core-5.7 (5.7.17-0ubuntu0.16.04.2) ...

Processing triggers for man-db (2.7.5-1) ...

Processing triggers for libc-bin (2.23-0ubuntu5) ...

[email protected]:~# sudo apt-get remove mysql-common

Reading package lists... Done

Building dependency tree       

Reading state information... Done

The following package was automatically installed and is no longer required:

  mysql-client-core-5.7

Use 'sudo apt autoremove' to remove it.

The following packages will be REMOVED:

  mysql-client mysql-client-5.7 mysql-common

0 upgraded, 0 newly installed, 3 to remove and 48 not upgraded.

After this operation, 34.4 MB disk space will be freed.

Do you want to continue? [Y/n] y

(Reading database ... 100103 files and directories currently installed.)

Removing mysql-client (5.7.17-0ubuntu0.16.04.2) ...

Removing mysql-client-5.7 (5.7.17-0ubuntu0.16.04.2) ...

Removing mysql-common (5.7.17-0ubuntu0.16.04.2) ...

Processing triggers for man-db (2.7.5-1) ...

4、殘留資料移除。

[email protected]:~# dpkg -l |grep ^rc|awk '{print $2}' |sudo xargs dpkg -P 

(Reading database ... 100056 files and directories currently installed.)

Removing mysql-common (5.7.17-0ubuntu0.16.04.2) ...

Purging configuration files for mysql-common (5.7.17-0ubuntu0.16.04.2) ...

Removing mysql-server-5.7 (5.7.17-0ubuntu0.16.04.2) ...

Purging configuration files for mysql-server-5.7 (5.7.17-0ubuntu0.16.04.2) ...

[email protected]:~# sudo dpkg -i mysql-apt-config_0.7.2-1_all.deb                                                                                                    

dpkg: error processing archive mysql-apt-config_0.7.2-1_all.deb (--install):

 cannot access archive: No such file or directory

Errors were encountered while processing:

 mysql-apt-config_0.7.2-1_all.deb

[email protected]:~# sudo dpkg -i mysql-apt-config_0.7.2-1_all.deb

dpkg: error processing archive mysql-apt-config_0.7.2-1_all.deb (--install):

 cannot access archive: No such file or directory

Errors were encountered while processing:

 mysql-apt-config_0.7.2-1_all.deb

[email protected]:~# sudo apt-get update

Hit:1 http://mirrors.cloud.aliyuncs.com/ubuntu xenial InRelease

Hit:2 http://mirrors.cloud.aliyuncs.com/ubuntu xenial-security InRelease

Hit:3 http://mirrors.cloud.aliyuncs.com/ubuntu xenial-updates InRelease

Hit:4 http://mirrors.cloud.aliyuncs.com/ubuntu xenial-proposed InRelease

Hit:5 http://mirrors.cloud.aliyuncs.com/ubuntu xenial-backports InRelease

Reading package lists... Done 

[email protected]:~# sudo netstat -tap | grep mysql 

[email protected]:~#