Mysql Startup failure Common error

You can make a mistake in order.

MySQL startup times wrong: starting MySQL ... error! The server quit without updating PID file (/opt/mysql-master/data/mysql.pid) Workaround:

1, may be/opt/mysql-master/data/data directory MySQL user does not have permissions (modify the data directory permissions)

Workaround: Give permission, execute "chown-r mysql.mysql/opt/mysql-master/data" and restart Mysqld

2. The MySQL process may already exist in the process

WORKAROUND: Use the command "Ps-ef|grep mysqld" to see if there is a mysqld process, kill with "kill-9 process number" and then restart mysqld!

3, may be the second time to install MySQL on the machine, there are residual data affect the start of the service.

Workaround: Go to the MySQL binary log directory to see if there is a mysql-binlog.index, and quickly delete it.

4. mysql will use the/ETC/MY.CNF configuration file when it is not specified at startup, please open this file to see if there is a specified data directory (DATADIR) under [mysqld].

WORKAROUND: Please set this line under [mysqld]: DataDir =/opt/mysql-master/data

5. skip-federated field Problem

Workaround: Check the/etc/my.cnf file for any skip-federated fields that have not been commented out, and if so, comment them out immediately.

6. Error log directory does not exist

Workaround: Use "Chown" "chmod" command to give MySQL owner and permissions

7, the disaster of SELinux, if it is a CentOS system, default will open SELinux

Workaround: Temporarily change to warning mode first: [[email protected] php]# Setenforce 0

Then open the/etc/sysconfig/selinux and change the selinux=enforcing to selinux=disabled

8, you can try to mysql.cnf default file open, troubleshooting is not a configuration file errors.

Common configuration errors are:

Check the configuration file/etc/my.cnf There is no innodb_buffer_pool_size this parameter

Innodb_buffer_pool_size: The main role is to cache the index of the InnoDB table, data, buffer when inserting data;

Default value: 128M;

Dedicated MySQL server sets the size of this value: System memory is 70%-80% best.

If your system has little memory, look at this parameter and set it to a smaller value.

Warm tip: Remember to turn on MySQL error log, convenient for your own troubleshooting.

VIM/ETC/MY.CNF You can edit according to your own my.cnf file.

[Mysql_safe]

Log-error =/data/mysql-master/logs/error.log

Mysql Startup failure Common error