为什么它由于 ERROR 2002 无法连接到本地 mysql 服务器？

Question

我从存储库安装了 mysql-server，并想将 datadir 更改为自定义位置。将 datadir 设置为 /var/lib/mysql 我能够启动服务器，但是到新位置时出现错误。

ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)

以下是对 my.cnf 的更改：

user            = mysql
pid-file        = /var/run/mysqld/mysqld.pid
socket          = /var/run/mysqld/mysqld.sock
port            = 3306
basedir         = /usr
datadir         = /media/db2/mysql
tmpdir          = /tmp
lc-messages-dir = /usr/share/mysql
skip-external-locking

我正在搜索这个网站和其他网站，遇到这个链接并更改了我的 /etc/apparmor.d/usr.sbin.mysqld 文件。这是相关的变化

#  /var/lib/mysql/ r,
#  /var/lib/mysql/** rwk,
  /media/db2/mysql/ r,
  /media/db2/mysql/** rwk,

然后我能够重新启动mysql服务

sudo service mysql restart

但无法打开mysql

mysql -u root -p

我遇到了另一个与上述类似的错误。所以我搜索了更多并将文件从 /var/lib/mysql 复制到我的新目录。

现在，当我尝试重新启动 mysql 时，它只是挂起。/var/log/mysql/error.log 中的日志文件显示：

130125 12:35:41  InnoDB: Waiting for the background threads to start
130125 12:35:42 InnoDB: 1.1.8 started; log sequence number 1595675
130125 12:35:42 [Note] Server hostname (bind-address): '127.0.0.1'; port: 3306
130125 12:35:42 [Note]   - '127.0.0.1' resolves to '127.0.0.1';
130125 12:35:42 [Note] Server socket created on IP: '127.0.0.1'.
130125 12:35:42 [ERROR] /usr/sbin/mysqld: Can't find file: './mysql/host.frm' (errno: 13)
130125 12:35:42 [ERROR] Fatal error: Can't open and lock privilege tables: Can't find         file: './mysql/host.frm' (errno: 13)
130125 12:35:43 [Note] Plugin 'FEDERATED' is disabled.
/usr/sbin/mysqld: Can't find file: './mysql/plugin.frm' (errno: 13)
130125 12:35:43 [ERROR] Can't open the mysql.plugin table. Please run mysql_upgrade     to create it.
130125 12:35:43 InnoDB: The InnoDB memory heap is disabled
130125 12:35:43 InnoDB: Mutexes and rw_locks use GCC atomic builtins
130125 12:35:43 InnoDB: Compressed tables use zlib 1.2.7
130125 12:35:43 InnoDB: Using Linux native AIO
130125 12:35:43 InnoDB: Initializing buffer pool, size = 128.0M
130125 12:35:43 InnoDB: Completed initialization of buffer pool
130125 12:35:43 InnoDB: highest supported file format is Barracuda.
InnoDB: Log scan progressed past the checkpoint lsn 49439
130125 12:35:43  InnoDB: Database was not shut down normally!
InnoDB: Starting crash recovery.
InnoDB: Reading tablespace information from the .ibd files...
InnoDB: Restoring possible half-written data pages from the doublewrite
InnoDB: buffer...
InnoDB: Doing recovery: scanned up to log sequence number 1595675
130125 12:35:45  InnoDB: Starting an apply batch of log records to the database...
InnoDB: Progress in percents: 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65     66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99
InnoDB: Apply batch completed

我认为 appamor 是问题所在，它基本上是一个权限问题......

这是我希望 db 文件所在位置的权限...

$ ls /media/db2/mysql -al
total 28732
drwxrwxrwx 3 mysql root      4096 Jan 25 12:39 .
drwxr-xr-x 4 root  root      4096 Jan 25  2013 ..
-rw-rw---- 1 mysql mysql 18874368 Jan 25  2013 ibdata1
-rw-rw---- 1 mysql mysql  5242880 Jan 25 12:39 ib_logfile0
-rw-rw---- 1 mysql mysql  5242880 Jan 25  2013 ib_logfile1
drwx------ 2 root  root      4096 Jan 25  2013 mysql

任何帮助，将不胜感激。谢谢！

Answer 1

我能够通过 chowning datadir 文件夹来解决此问题，以便 mysql 用户成为所有者

sudo chown mysql:mysql /mysql/data/dir

不确定这是否能解决其他人的问题，但这对我有用。