CentOS下如何徹底卸載MySQL？解決卸載不乾淨的問題

CentOS下如何徹底卸載MySQL？解決卸載不乾淨的問題

系統：CentOS 6.5，MySQL：MySql 5.6

這裏主要解決使用rpm安裝的卸載問題，安裝方法見：CentOS安裝mysql*.rpm提示conflicts with file from package的解決辦法

雖說這裏的是使用rpm安裝的卸載問題，我以爲使用yum方式安裝的若是遇到相同的問題也同樣適用。

查看已經安裝的服務

rpm –qa|grep -i mysql

-i 做用是不區分大小寫

yum remove mysql mysql-server mysql-libs compat-mysql51
rm -rf /var/lib/mysql
rm /etc/my.cnf
查看是否還有mysql軟件：
rpm -qa|grep mysql
有的話繼續刪除

能夠看到有兩個安裝包

MySQL-server-5.6.19-1.linux_glibc2.5.x86_64.rpm
MySQL-client-5.6.19-1.linux_glibc2.5.x86_64.rpm

刪除這兩個服務(去掉後綴)

rpm –e MySQL-client-5.6.19-1.linux_glibc2.5.x86_64
rpm -e MySQL-server-5.6.19-1.linux_glibc2.5.x86_64

查看殘留的目錄：

whereis mysql

而後刪除mysql目錄：

rm –rf /usr/lib64/mysql

刪除相關文件：

rm –rf /usr/my.cnf
rm -rf /root/.mysql_sercret

最關鍵的：

rm -rf /var/lib/mysql

若是這個目錄若是不刪除，再從新安裝以後，密碼仍是以前的密碼，不會從新初始化！

網上查了好久都沒有文章提到這個，最後仍是本身摸索找出來的。

卸載完成！怎麼肯定是否是真的卸載乾淨了呢？

一是看安裝輸出：

若是沒有卸載乾淨，安裝server時輸入只有兩行：

[root @localhost opt]# rpm -ivh MySQL-server-5.6.19-1.linux_glibc2.5.x86_64.rpm
Preparing...                ########################################### [100%]
   1:MySQL-server           ########################################### [100%]

卸載乾淨了安裝輸入以下：

[root @localhost opt]# rpm -ivh MySQL-server-5.6.19-1.linux_glibc2.5.x86_64.rpm
Preparing...                ########################################### [100%]
   1:MySQL-server           ########################################### [100%]
2014-09-23 07:22:43 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).
2014-09-23 07:22:43 26041 [Note] InnoDB: Using atomics to ref count buffer pool pages
2014-09-23 07:22:43 26041 [Note] InnoDB: The InnoDB memory heap is disabled
2014-09-23 07:22:43 26041 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins
2014-09-23 07:22:43 26041 [Note] InnoDB: Compressed tables use zlib 1.2.3
2014-09-23 07:22:43 26041 [Note] InnoDB: Using Linux native AIO
2014-09-23 07:22:43 26041 [Note] InnoDB: Using CPU crc32 instructions
2014-09-23 07:22:43 26041 [Note] InnoDB: Initializing buffer pool, size = 128.0M
2014-09-23 07:22:43 26041 [Note] InnoDB: Completed initialization of buffer pool
2014-09-23 07:22:43 26041 [Note] InnoDB: The first specified data file ./ibdata1 did not exist: a new database to be created!
2014-09-23 07:22:43 26041 [Note] InnoDB: Setting file ./ibdata1 size to 12 MB
2014-09-23 07:22:43 26041 [Note] InnoDB: Database physically writes the file full: wait...
2014-09-23 07:22:43 26041 [Note] InnoDB: Setting log file ./ib_logfile101 size to 48 MB
2014-09-23 07:22:43 26041 [Note] InnoDB: Setting log file ./ib_logfile1 size to 48 MB
2014-09-23 07:22:45 26041 [Note] InnoDB: Renaming log file ./ib_logfile101 to ./ib_logfile0
2014-09-23 07:22:45 26041 [Warning] InnoDB: New log files created, LSN=45781
2014-09-23 07:22:45 26041 [Note] InnoDB: Doublewrite buffer not found: creating new
2014-09-23 07:22:45 26041 [Note] InnoDB: Doublewrite buffer created
2014-09-23 07:22:45 26041 [Note] InnoDB: 128 rollback segment(s) are active.
2014-09-23 07:22:45 26041 [Warning] InnoDB: Creating foreign key constraint system tables.
2014-09-23 07:22:45 26041 [Note] InnoDB: Foreign key constraint system tables created
2014-09-23 07:22:45 26041 [Note] InnoDB: Creating tablespace and datafile system tables.
2014-09-23 07:22:45 26041 [Note] InnoDB: Tablespace and datafile system tables created.
2014-09-23 07:22:45 26041 [Note] InnoDB: Waiting for purge to start
2014-09-23 07:22:45 26041 [Note] InnoDB: 5.6.19 started; log sequence number 0
A random root password has been set. You will find it in '/root/.mysql_secret'.
2014-09-23 07:22:46 26041 [Note] Binlog end
2014-09-23 07:22:46 26041 [Note] InnoDB: FTS optimize thread exiting.
2014-09-23 07:22:46 26041 [Note] InnoDB: Starting shutdown...
2014-09-23 07:22:48 26041 [Note] InnoDB: Shutdown completed; log sequence number 1625977


2014-09-23 07:22:48 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).
2014-09-23 07:22:48 26065 [Note] InnoDB: Using atomics to ref count buffer pool pages
2014-09-23 07:22:48 26065 [Note] InnoDB: The InnoDB memory heap is disabled
2014-09-23 07:22:48 26065 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins
2014-09-23 07:22:48 26065 [Note] InnoDB: Compressed tables use zlib 1.2.3
2014-09-23 07:22:48 26065 [Note] InnoDB: Using Linux native AIO
2014-09-23 07:22:48 26065 [Note] InnoDB: Using CPU crc32 instructions
2014-09-23 07:22:48 26065 [Note] InnoDB: Initializing buffer pool, size = 128.0M
2014-09-23 07:22:48 26065 [Note] InnoDB: Completed initialization of buffer pool
2014-09-23 07:22:48 26065 [Note] InnoDB: Highest supported file format is Barracuda.
2014-09-23 07:22:48 26065 [Note] InnoDB: 128 rollback segment(s) are active.
2014-09-23 07:22:48 26065 [Note] InnoDB: Waiting for purge to start
2014-09-23 07:22:48 26065 [Note] InnoDB: 5.6.19 started; log sequence number 1625977
2014-09-23 07:22:48 26065 [Note] Binlog end
2014-09-23 07:22:48 26065 [Note] InnoDB: FTS optimize thread exiting.
2014-09-23 07:22:48 26065 [Note] InnoDB: Starting shutdown...
2014-09-23 07:22:50 26065 [Note] InnoDB: Shutdown completed; log sequence number 1625987




A RANDOM PASSWORD HAS BEEN SET FOR THE MySQL root USER !
You will find that password in '/root/.mysql_secret'.

You must change that password on your first connect,
no other statement but 'SET PASSWORD' will be accepted.
See the manual for the semantics of the 'password expired' flag.

Also, the account for the anonymous user has been removed.

In addition, you can run:

  /usr/bin/mysql_secure_installation

which will also give you the option of removing the test database.
This is strongly recommended for production servers.

See the manual for more instructions.

Please report any problems at http://bugs.mysql.com/

The latest information about MySQL is available on the web at

  http://www.mysql.com

Support MySQL by buying support/licenses at http://shop.mysql.com

New default config file was created as /usr/my.cnf and
will be used by default by the server when you start it.
You may edit this file to change server settings

最後一段中提示了重要信息，不少人由於不喜歡讀英文，致使接下來不知道怎麼操做！

二就是安裝完成，啓動服務以後

使用命令：「mysql -uroot -p」輸入你以前安裝後設置的密碼，看能不能登陸，若是還能夠登陸，說明沒有卸載乾淨！