mysql5.6 error 2002_MySQL/MariaDB错误：ERROR 2002 (HY000)的解决方法

查看一下hostname.err文件：

150404 22:48:57 mysqld_safe The server is respawning too fast. Sleeping for 1 second.

150404 22:48:58 mysqld_safe Number of processes running now: 0

150404 22:48:58 mysqld_safe mysqld restarted

150404 22:48:58 [Note] InnoDB: Using mutexes to ref count buffer pool pages

150404 22:48:58 [Note] InnoDB: The InnoDB memory heap is disabled

150404 22:48:58 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins

150404 22:48:58 [Note] InnoDB: Memory barrier is not used

150404 22:48:58 [Note] InnoDB: Compressed tables use zlib 1.2.3

150404 22:48:58 [Note] InnoDB: Using Linux native AIO

150404 22:48:58 [Note] InnoDB: Using CPU crc32 instructions

150404 22:48:58 [Note] InnoDB: Initializing buffer pool, size = 128.0M

150404 22:48:58 [Note] InnoDB: Completed initialization of buffer pool

150404 22:48:58 [Note] InnoDB: Highest supported file format is Barracuda.

150404 22:48:58 [Note] InnoDB: 128 rollback segment(s) are active.

150404 22:48:58 [Note] InnoDB: Waiting for purge to start

150404 22:48:58 [Note] InnoDB:  Percona XtraDB (http://www.percona.com) 5.6.22-72.0 started; log sequence number 1681155

150404 22:48:58 [Note] Plugin 'FEEDBACK' is disabled.

150404 22:48:58 [Note] Server socket created on IP: '::'.

150404 22:48:58 [ERROR] mysqld: Error writing file '/var/lib/mysql/localhost.localdomain.pid' (Errcode: 28 "No space left on device")

150404 22:48:58150404 22:48:58 mysqld_safe Number of processes running now: 0

150404 22:48:58 mysqld_safe mysqld restarted

150404 22:48:58 [Note] InnoDB: Using mutexes to ref count buffer pool pages

150404 22:48:58 [Note] InnoDB: The InnoDB memory heap is disabled

150404 22:48:58 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins

150404 22:48:58 [Note] InnoDB: Memory barrier is not used

150404 22:48:58 [Note] InnoDB: Compressed tables use zlib 1.2.3

150404 22:48:58 [Note] InnoDB: Using Linux native AIO

150404 22:48:58 [Note] InnoDB: Using CPU crc32 instructions

150404 22:48:58 [Note] InnoDB: Initializing buffer pool, size = 128.0M

150404 22:48:58 [Note] InnoDB: Completed initialization of buffer pool

150404 22:48:58 [Note] InnoDB: Highest supported file format is Barracuda.

150404 22:48:58 [Note] InnoDB: 128 rollback segment(s) are active.

150404 22:48:58 [Note] InnoDB: Waiting for purge to start

150404 22:48:58 [Note] InnoDB:  Percona XtraDB (http://www.percona.com) 5.6.22-72.0 started; log sequence number 1681155

150404 22:48:58 [Note] Plugin 'FEEDBACK' is disabled.

150404 22:48:58 [Note] Server socket created on IP: '::'.

150404 22:48:58 [ERROR] mysqld: Error writing file '/var/lib/mysql/localhost.localdomain.pid' (Errcode: 28 "No space left on device")

150404 22:48:58 [ERROR] Can't start server: can't create PID file: No space left on device

根据以上红色部分我们可以推断该问题的原因很可能跟存储空间有关，因此李科查看一下空间：

[root@localhost ~]#df -h

Filesystem      Size  Used Avail Use% Mounted on

/dev/sda2        11G  9.9G  9.0M 100% /               -----果然空间满了

tmpfs           1.9G     0  1.9G   0% /dev/shm

/dev/sda1       291M   39M  238M  14% /boot

[root@localhost /]#cd pgarchlog     ---初步判定可能是由于在同一台机器上的PostgreSQL的归档日志导致的

[root@localhost pgarchlog]# ls

music

[root@localhost pgarchlog]# du -sm

5694.                                        ----10G的空间，PostgreSQL的归档日志占了5.6G

清理PostgreSQL的归档日志：

[root@localhost music]# rm -fr  00000003*

[root@localhost music]#df -h

Filesystem      Size  Used Avail Use% Mounted on

/dev/sda2        11G  4.5G  5.4G  46% /                 ---------可以看到空间释放了

tmpfs           1.9G     0  1.9G   0% /dev/shm

/dev/sda1       291M   39M  238M  14% /boot

此时发现hostname.err里面还有一些报错信息：

[root@localhost music]#tail -f /var/lib/mysql/localhost.localdomain.err

150404 22:54:32 [ERROR] InnoDB: Unable to lock ./ibdata1, error: 11

150404 22:54:32 [Note] InnoDB: Check that you do not already have another mysqld process using the same InnoDB data or log files.

150404 22:54:33 [ERROR] InnoDB: Unable to lock ./ibdata1, error: 11

150404 22:54:33 [Note] InnoDB: Check that you do not already have another mysqld process using the same InnoDB data or log files.

150404 22:54:34 [ERROR] InnoDB: Unable to lock ./ibdata1, error: 11

150404 22:54:34 [Note] InnoDB: Check that you do not already have another mysqld process using the same InnoDB data or log files.

150404 22:54:35 [ERROR] InnoDB: Unable to lock ./ibdata1, error: 11

150404 22:54:35 [Note] InnoDB: Check that you do not already have another mysqld process using the same InnoDB data or log files.

150404 22:54:36 [ERROR] InnoDB: Unable to lock ./ibdata1, error: 11

150404 22:54:36 [Note] InnoDB: Check that you do not already have another mysqld process using the same InnoDB data or log files.

150404 22:54:37 [ERROR] InnoDB: Unable to lock ./ibdata1, error: 11

150404 22:54:37 [Note] InnoDB: Check that you do not already have another mysqld process using the same InnoDB data or log files.

150404 22:54:38 [ERROR] InnoDB: Unable to lock ./ibdata1, error: 11

150404 22:54:38 [Note] InnoDB: Check that you do not already have another mysqld process using the same InnoDB data or log files.

150404 22:54:39 [ERROR] InnoDB: Unable to lock ./ibdata1, error: 11

150404 22:54:39 [Note] InnoDB: Check that you do not already have another mysqld process using the same InnoDB data or log files.

150404 22:54:40 mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql

150404 22:54:40 [Note] InnoDB: Using mutexes to ref count buffer pool pages

150404 22:54:40 [Note] InnoDB: The InnoDB memory heap is disabled

150404 22:54:40 [Note] InnoDB: Mutexes and rw_locks use GCC atomic builtins

150404 22:54:40 [Note] InnoDB: Memory barrier is not used

150404 22:54:40 [Note] InnoDB: Compressed tables use zlib 1.2.3

150404 22:54:40 [Note] InnoDB: Using Linux native AIO

150404 22:54:40 [Note] InnoDB: Using CPU crc32 instructions

150404 22:54:40 [ERROR] InnoDB: Unable to lock ./ibdata1, error: 11

150404 22:54:40 [Note] InnoDB: Check that you do not already have another mysqld process using the same InnoDB data or log files.

150404 22:54:40 [Note] InnoDB: Initializing buffer pool, size = 128.0M

150404 22:54:40 [Note] InnoDB: Completed initialization of buffer pool

150404 22:54:40 [ERROR] InnoDB: Unable to lock ./ibdata1, error: 11

150404 22:54:40 [Note] InnoDB: Check that you do not already have another mysqld process using the same InnoDB data or log files.

150404 22:54:40 [Note] InnoDB: Retrying to lock the first data file

150404 22:54:41 [ERROR] InnoDB: Unable to lock ./ibdata1, error: 11

150404 22:54:41 [Note] InnoDB: Check that you do not already have another mysqld process using the same InnoDB data or log files.

150404 22:54:41 [ERROR] InnoDB: Unable to lock ./ibdata1, error: 11

150404 22:54:41 [Note] InnoDB: Check that you do not already have another mysqld process using the same InnoDB data or log files.

150404 22:54:42 [ERROR] InnoDB: Unable to lock ./ibdata1, error: 11

150404 22:54:42 [Note] InnoDB: Check that you do not already have another mysqld process using the same InnoDB data or log files.

150404 22:54:42 [ERROR] InnoDB: Unable to lock ./ibdata1, error: 11

150404 22:54:42 [Note] InnoDB: Check that you do not already have another mysqld process using the same InnoDB data or log files.

150404 22:54:43 [ERROR] InnoDB: Unable to lock ./ibdata1, error: 11

150404 22:54:43 [Note] InnoDB: Check that you do not already have another mysqld process using the same InnoDB data or log files.

150404 22:54:43 [ERROR] InnoDB: Unable to lock ./ibdata1, error: 11

150404 22:54:43 [Note] InnoDB: Check that you do not already have another mysqld process using the same InnoDB data or log files.

150404 22:54:44 [ERROR] InnoDB: Unable to lock ./ibdata1, error: 11

150404 22:54:44 [Note] InnoDB: Check that you do not already have another mysqld process using the same InnoDB data or log files.

150404 22:54:44 [ERROR] InnoDB: Unable to lock ./ibdata1, error: 11

150404 22:54:44 [Note] InnoDB: Check that you do not already have another mysqld process using the same InnoDB data or log files.

此时MySQL的启动和关闭还有一些小问题：

[root@localhost ~]#service mysql start

Starting MySQL SUCCESS!

[root@localhost ~]#service mysql stop

ERROR! MySQL server PID file could not be found!

[root@localhost ~]# service mysql start

Starting MySQL SUCCESS!

结合刚才的err日志看，应该是有进程打瞌睡没听到指令也没释放资源，就“杀”了他吧... ...

[root@localhost /]#ps -ef|grep mysql

root      41597      1  1 22:44 pts/1    00:00:17 /bin/sh /usr/bin/mysqld_safe --datadir=/var/lib/mysql --pid-file=/var/lib/mysql/localhost.localdomain.pid

mysql     94579  41597  0 22:52 pts/1    00:00:00 /usr/sbin/mysqld --basedir=/usr --datadir=/var/lib/mysql --plugin-dir=/usr/lib64/mysql/plugin --user=mysql --log-error=/var/lib/mysql/localhost.localdomain.err --pid-file=/var/lib/mysql/localhost.localdomain.pid

root      94820  44278  0 22:55 pts/0    00:00:00 mysql

root      94865  58733  0 23:01 pts/1    00:00:00 grep mysql

[root@localhost /]# service mysql stop

ERROR! MySQL server PID file could not be found!

[root@localhost /]#kill -9 41597

[root@localhost /]# kill -9 94579

[root@localhost /]# kill -9 94820

[root@localhost /]# ps -ef|grep mysql

root      94892  58733  1 23:03 pts/1    00:00:00 grep mysql

[root@localhost /]#service mysql stop

ERROR! MySQL server PID file could not be found!

[root@localhost /]# service mysql start

Starting MySQL. SUCCESS!

[root@localhost /]# service mysql stop

Shutting down MySQL... SUCCESS!

[root@localhost /]# service mysql start

Starting MySQL. SUCCESS!

经过几次重启，数据库终于恢复正常！~~~

验证一下数据库：

查看当前登录用户：

MariaDB [(none)]> select current_user();

+----------------+

| current_user() |

+----------------+

| eric@localhost |

+----------------+

1 row in set (0.01 sec)

登陆MUSIC数据库看看：

[root@localhost ~]# mysql -u eric -D music

Reading table information for completion of table and column names

You can turn off this feature to get a quicker startup with -A

Welcome to the MariaDB monitor.  Commands end with ; or \g.

Your MariaDB connection id is 30

Server version: 10.0.17-MariaDB MariaDB Server

Copyright (c) 2000, 2015, Oracle, MariaDB Corporation Ab and others.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

MariaDB [music]> insert into summary values(5,'Eric Gao is a PostgreSQL DBA');

Query OK, 1 row affected (0.01 sec)

MariaDB [music]> update summary set id=3 where info like '%PostgreSQL%';

Query OK, 1 row affected (0.01 sec)

Rows matched: 1  Changed: 1  Warnings: 0

MariaDB [music]> update summary set id=5 where info like '%AIX%';

Query OK, 1 row affected (0.02 sec)

Rows matched: 1  Changed: 1  Warnings: 0

MariaDB [music]> select * from summary order by id;

+------+------------------------------+

| id   | info                         |

+------+------------------------------+

|    1 | Eric Gao is a Oracle DBA     |

|    2 | Eric Gao is a MySQL DBA      |

|    3 | Eric Gao is a PostgreSQL DBA |

|    4 | Eric Gao is a Linux  SA      |

|    5 | Eric Gao is a AIX  SA        |

+------+------------------------------+

5 rows in set (0.00 sec)

OK，数据可访问，也可插入新的数据！~~~