0 查看mysql进程 ps -ef|grep mysql
[root@localhost mysql]# ps -ef|grep mysql root 10626 7899 0 09:14 pts/0 00:00:00 mysql -u zt_dev -p root 22002 10757 0 14:32 pts/1 00:00:00 grep --color=auto mysql mysql 28782 1 0 3月04 ? 00:00:00 /bin/sh /usr/bin/mysqld_safe --basedir=/usr mysql 28997 28782 3 3月04 ? 13:15:11 /usr/sbin/mysqld --basedir=/usr --datadir=/var/lib/mysql --plugin-dir=/usr/lib64/mysql/plugin --log-error=/var/log/mysqld.log --pid-file=/var/run/mysqld/mysqld.pid --socket=/var/lib/mysql/mysql.sock
查看文件安装路径 whereis mysql
[root@localhost mysql]# whereis mysql mysql: /usr/bin/mysql /usr/lib64/mysql /usr/share/mysql /usr/share/man/man1/mysql.1.gz
查询运行文件所在路径 which mysql
[root@localhost mysql]# which mysql
/usr/bin/mysql (运行文件是一堆乱码 看不懂 不要进去看了)
1 登录mysql后执行命令 show variables like '%dir%';
mysql> show variables like '%dir%'; +-----------------------------------------+----------------------------+ | Variable_name | Value | +-----------------------------------------+----------------------------+ | basedir | /usr/ | | binlog_direct_non_transactional_updates | OFF | | character_sets_dir | /usr/share/mysql/charsets/ | | datadir | /var/lib/mysql/ | | ignore_db_dirs | | | innodb_data_home_dir | | | innodb_log_group_home_dir | ./ | | innodb_max_dirty_pages_pct | 75 | | innodb_max_dirty_pages_pct_lwm | 0 | | innodb_tmpdir | | | innodb_undo_directory | . | | lc_messages_dir | /usr/share/mysql/ | | plugin_dir | /usr/lib64/mysql/plugin/ | | slave_load_tmpdir | /tmp | | tmpdir | /tmp | +-----------------------------------------+----------------------------+ 15 rows in set (0.00 sec)
2 数据库目录：/var/lib/mysql/
配置文件my.cnf中 会 有一条配置 datadir=/var/lib/mysql 指定数据库目录位置
linux 和 navicate 显示的数据库目录一样 如下
3 配置文件 /etc/my.cnf
[root@localhost mysql]# cat /etc/my.cnf # For advice on how to change settings please see # http://dev.mysql.com/doc/refman/5.6/en/server-configuration-defaults.html [mysqld] character_set_server = utf8 collation-server=utf8_general_ci # # Remove leading # and set to the amount of RAM for the most important data # cache in MySQL. Start at 70% of total RAM for dedicated server, else 10%. # innodb_buffer_pool_size = 128M # # Remove leading # to turn on a very important data integrity option: logging # changes to the binary log between backups. # log_bin # # Remove leading # to set options mainly useful for reporting servers. # The server defaults are faster for transactions and fast SELECTs. # Adjust sizes as needed, experiment to find the optimal values. # join_buffer_size = 128M # sort_buffer_size = 2M # read_rnd_buffer_size = 2M datadir=/var/lib/mysql mysql数据存储在这里 socket=/var/lib/mysql/mysql.sock # Disabling symbolic-links is recommended to prevent assorted security risks symbolic-links=0 # Recommended in standard MySQL setup sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES [mysqld_safe] log-error=/var/log/mysqld.log pid-file=/var/run/mysqld/mysqld.pid # Maximum length for GROUP_CONCAT group_concat_max_len = -1
4 mysql.sock的作用
对mysql.sock来说，其作用是程序与mysqlserver处于同一台机器，发起本地连接时可用
例如你无须定义连接host的具体IP地址，只要为空或localhost就可以。
在此种情况下，即使你改变mysql的外部port也是一样可能正常连接。
因为你在my.ini中或my.cnf中改变端口后，mysql.sock是随每一次 mysql server启动生成的。已经根据你在更改完my.cnf后重启mysql时重新生成了一次，信息已跟着变更。
那么对于外部连接，必须是要变更port才能连接的。
linux下安装mysql连接的时候经常回提示说找不到mysql.sock文件，解决办法很简单：
如果是新安装的mysql，提示找不到文件，就搜索下，指定正确的位置。
如果mysql.sock文件误删的话，就需要重启mysql服务，如果重启成功的话会在datadir目录下面生成mysql.sock 到时候指定即可。
5 pid文件 /var/run/mysqld/mysqld.pid
当mysql实例启动时，会将自己的进程id写入一个文件中，
该文件即为pid文件。
6 错误日志log-error文件 /var/log/mysqld.log
[root@localhost mysql]# tail -f /var/log/mysqld.log Version: '5.6.44' socket: '/var/lib/mysql/mysql.sock' port: 3306 MySQL Community Server (GPL) 2020-03-04 10:26:03 28997 [Warning] IP address 'xxx.xxx.x.xxx' could not be resolved: Name or service not known 2020-03-04 10:26:45 28997 [Warning] IP address 'xxx.xxx.x.xx' could not be resolved: Name or service not known