mysql安装错误：无法为MySQL“ root”用户设置密码

Question

许多人遇到此错误，但是没有提供的解决方案适合我的情况：

在我的ubuntu 14.04服务器中，mysql-server 5.5正常运行，由于某种原因，我们两个家伙试图升级到5.6，经过一番混乱的操作，他们失败了，只有5.6-client，并且安装了mysql-commn，所以我实际上不知道它们的详细操作，然后我尝试将其降级到5.5，如下所示：

killall -9 mysql
killall -9 mysqld
apt-get purge mysql-*
remove /etc/myql
apt-get install mysql-sever-5.5

出现错误：

 ┌───────────────────────Configuring mysql-server-5.5─────────────────────────┐ 
 │ Unable to set password for the MySQL "root" user                           │ 
 ├────────────────────────────────────────────────────────────────────────────┤

和安装日志如下：

Setting up mysql-server-core-5.5 (5.5.54-0ubuntu0.14.04.1) ...
Setting up mysql-server-5.5 (5.5.54-0ubuntu0.14.04.1) ...
170218  2:15:57 [Warning] Using unique option prefix key_buffer instead of key_buffer_size is deprecated and will be removed in a future release. Please use the full name instead.
170218  2:15:57 [Note] Ignoring --secure-file-priv value as server is running with --bootstrap.
170218  2:15:57 [Note] /usr/sbin/mysqld (mysqld 5.5.54-0ubuntu0.14.04.1) starting as process 9038 ...
start: Job failed to start
invoke-rc.d: initscript mysql, action "start" failed.
dpkg: error processing package mysql-server-5.5 (--configure):
 subprocess installed post-installation script returned error exit status 1
Processing triggers for libc-bin (2.19-0ubuntu6.7) ...
Errors were encountered while processing:
 mysql-server-5.5
E: Sub-process /usr/bin/dpkg returned an error code (1)

错误日志是这样的：

 170218  2:15:57 [ERROR] /usr/sbin/mysqld: Incorrect information in file: './mysql/tables_priv.frm'
ERROR: 1033  Incorrect information in file: './mysql/tables_priv.frm'
170218  2:15:57 [ERROR] Aborting

170218  2:15:57 [Note] /usr/sbin/mysqld: Shutdown complete

170218  2:15:57 [Warning] Using unique option prefix myisam-recover instead of myisam-recover-options is deprecated and
 will be removed in a future release. Please use the full name instead.
170218  2:15:57 [Note] Plugin 'FEDERATED' is disabled.
170218  2:15:57 InnoDB: The InnoDB memory heap is disabled
170218  2:15:57 InnoDB: Mutexes and rw_locks use GCC atomic builtins
170218  2:15:57 InnoDB: Compressed tables use zlib 1.2.8
170218  2:15:57 InnoDB: Using Linux native AIO
170218  2:15:57 InnoDB: Initializing buffer pool, size = 128.0M
170218  2:15:57 InnoDB: Completed initialization of buffer pool
InnoDB: Error: log file ./ib_logfile0 is of different size 0 50331648 bytes
InnoDB: than specified in the .cnf file 0 5242880 bytes!
170218  2:15:57 [ERROR] Plugin 'InnoDB' init function returned error.
170218  2:15:57 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed.
170218  2:15:57 [ERROR] Unknown/unsupported storage engine: InnoDB
170218  2:15:57 [ERROR] Aborting

170218  2:15:57 [Note] /usr/sbin/mysqld: Shutdown complete

那么，如何解决这个问题呢？有什么建议值得赞赏吗？

Answer 1

做这个：

sudo -i
service mysql stop
killall -KILL mysql mysqld_safe mysqld
apt-get --yes purge mysql-server mysql-client
apt-get --yes autoremove --purge
apt-get autoclean
deluser --remove-home mysql
delgroup mysql
rm -rf /etc/apparmor.d/abstractions/mysql /etc/apparmor.d/cache/usr.sbin.mysqld /etc/mysql /var/lib/mysql /var/log/mysql* /var/log/upstart/mysql.log* /var/run/mysqld
updatedb
exit

您可能还需要dpkg -l | grep mysql dpkg -l | grep mysql列出所有已安装的mysql软件包，然后为每个条目列出sudo apt-get purge mysql-common 。

如果完成了上述步骤，并且dpkg -l | grep mysql dpkg -l | grep mysql已运行，您可以尝试使用以下命令进行安装：

sudo apt-get install mysql-server-5.5

Answer 2

我在Ubuntu 16.04 LTS中安装MySQL 5.6版本时遇到相同的问题。 搜索并与朋友交谈后，我弄清楚了如何正确安装此程序。

首先备份数据库，然后执行以下命令：

$ sudo apt-get remove --purge *mysql/*
$ sudo apt-get autoremove
$ sudo apt-get autoclean
$ sudo rm -rf /var/lib/mysql
$ sudo apt install mysql-server-5.6
$ sudo apt install mysql-client-5.6