标签：mysql
环境：
[root@SQL-M ~]# cat /etc/redhat-release
CentOS release 6.8 (Final)
[root@SQL-M ~]# uname -r
2.6.32-642.el6.x86_64
开始安装配置：
[root@SQL-M ~]# cd /usr/local/src/
[root@SQL-M src]# wget http://mirrors.sohu.com/mysql/MySQL-5.5/mysql-5.5.55-linux2.6-x86_64.tar.gz
[root@SQL-M src]# ll -h
total 178M
-rw-r--r-- 1 root root 178M Apr 22 16:27 mysql-5.5.55-linux2.6-x86_64.tar.gz
[root@SQL-M src]# tar zxf mysql-5.5.55-linux2.6-x86_64.tar.gz -C /usr/local/ # 解压
[root@SQL-M src]# cd ..
[root@SQL-M local]# mv mysql-5.5.55-linux2.6-x86_64/ mysql-5.5.55 # 改名
[root@SQL-M local]# ln -s mysql-5.5.55 mysql # 做软连接
[root@SQL-M local]# useradd mysql -s /sbin/nologin -M # 建立系统用户
[root@SQL-M local]# mysql/scripts/mysql_install_db --basedir=/usr/local/mysql/ --datadir=/usr/local/mysql/data/ --user=mysql # 初始化数据库
[root@SQL-M local]# chown -R mysql:mysql mysql-5.5.55 # 对目录授权
[root@SQL-M local]# vi /etc/my.cnf # 创建配置文件，测试用的
[client] port=3306 socket= /usr/local/mysql/mysql.sock [mysqld] user = mysql datadir = /usr/local/mysql/data/ character-set-server = utf8 skip-character-set-client-handshake init-connect = ‘SET NAMES utf8‘ open_files_limit=1024 back_log = 600 max_connections = 800 max_connect_errors = 3000 table_cache = 614 external-locking = FALSE max_allowed_packet =8M sort_buffer_size = 1M join_buffer_size = 1M thread_cache_size = 100 thread_concurrency = 2 query_cache_size = 2M query_cache_limit = 1M query_cache_min_res_unit = 2k thread_stack = 192K tmp_table_size = 2M max_heap_table_size = 2M log-bin = /usr/local/mysql/data/mysql-bin binlog_cache_size = 1M max_binlog_cache_size = 1M max_binlog_size = 2M expire_logs_days = 7 key_buffer_size = 16M read_buffer_size = 1M read_rnd_buffer_size = 1M bulk_insert_buffer_size = 1M lower_case_table_names = 1 skip-name-resolve slave-skip-errors = 1032,1062 replicate-ignore-db=mysql server-id = 1 innodb_additional_mem_pool_size = 4M innodb_buffer_pool_size = 16M innodb_file_io_threads = 4 innodb_thread_concurrency = 8 innodb_flush_log_at_trx_commit = 2 innodb_log_buffer_size = 2M innodb_log_file_size = 4M innodb_log_files_in_group = 3 innodb_max_dirty_pages_pct = 90 innodb_lock_wait_timeout = 120 innodb_file_per_table = 0 [mysqldump] quick max_allowed_packet = 2M [mysqld_safe] log-error=/var/log/mysqld.log pid-file=/var/run/mysqld/mysqld.pid
[root@SQL-M local]# cp mysql/bin/* sbin/ # 复制执行命令到 sbin 下
[root@SQL-M local]# cp mysql/support-files/mysql.server /etc/init.d/mysqld # 生成启动脚本
[root@SQL-M local]# /etc/init.d/mysqld start # 直接启动服务
Starting MySQL...... SUCCESS!
[root@SQL-M ~]# netstat -lntup # 查看服务
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 0.0.0.0:3306 0.0.0.0:* LISTEN 7853/mysqld
[root@SQL-M ~]# lsof -i:3306
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
mysqld 7853 mysql 12u IPv4 24118 0t0 TCP *:mysql (LISTEN)
[root@SQL-M local]# mysqladmin -u root password # 给 root 密码，默认免密登录
Enter password:
[root@SQL-M local]# mysql -uroot -p # 交互式密码登录
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 3
Server version: 5.5.55-log MySQL Community Server (GPL)
Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type ‘help;‘ or ‘\h‘ for help. Type ‘\c‘ to clear the current input statement.
mysql>
mysql> show databases;
+--------------------+
| Database |
+--------------------+
| information_schema |
| mysql |
| performance_schema |
| test |
+--------------------+
4 rows in set (0.13 sec)
mysql> drop database test; # 删掉测试库
Query OK, 0 rows affected (0.00 sec)
mysql> select user,host from mysql.user;
+------+-----------+
| user | host |
+------+-----------+
| root | 127.0.0.1 |
| root | ::1 |
| | localhost |
| root | localhost |
| | sql-m |
| root | sql-m |
+------+-----------+
6 rows in set (0.11 sec)
mysql> drop user root@‘::1‘; # 把没用的用户删除
Query OK, 0 rows affected (0.14 sec)
mysql> drop user ‘‘@localhost;
Query OK, 0 rows affected (0.00 sec)
mysql> drop user ‘‘@‘sql-m‘;
Query OK, 0 rows affected (0.00 sec)
mysql> drop user root@‘sql-m‘;
Query OK, 0 rows affected (0.03 sec)
mysql> select user,host from mysql.user;
+------+-----------+
| user | host |
+------+-----------+
| root | 127.0.0.1 |
| root | localhost |
+------+-----------+
2 rows in set (0.00 sec)
mysql> flush privileges;
Query OK, 0 rows affected (0.00 sec)
mysql> quit
[root@SQL-M local]# mysqladmin -uroot -p123 password # 改密码
New password:
Confirm new password:
测试忘记root密码重新找回：
[root@SQL-M ~]# /etc/init.d/mysqld stop # 先停掉服务
Shutting down MySQL.. SUCCESS!
[root@SQL-M ~]# mysqld_safe --skip-grant-tables & # 忽略授权表方式启动服务
[1] 3685
170422 17:37:34 mysqld_safe Logging to ‘/var/log/mysqld.log‘.
170422 17:37:34 mysqld_safe Starting mysqld daemon with databases from /usr/local/mysql/data
[root@SQL-M ~]# 170422 17:37:39 mysqld_safe mysqld from pid file /var/run/mysqld/mysqld.pid ended
[1]+ Done mysqld_safe --skip-grant-tables
奇怪居然失败了！看一下日志先。。。
[root@SQL-M ~]# tail /var/log/mysqld.log
170422 17:39:41 InnoDB: Waiting for the background threads to start
170422 17:39:42 InnoDB: 5.5.55 started; log sequence number 1595668
170422 17:39:42 [Note] Recovering after a crash using /usr/local/mysql/data/mysql-bin
170422 17:39:42 [Note] Starting crash recovery...
170422 17:39:42 [Note] Crash recovery finished.
170422 17:39:42 [Note] Server hostname (bind-address): ‘0.0.0.0‘; port: 3306
170422 17:39:42 [Note] - ‘0.0.0.0‘ resolves to ‘0.0.0.0‘;
170422 17:39:42 [Note] Server socket created on IP: ‘0.0.0.0‘.
170422 17:39:42 [ERROR] /usr/local/sbin/mysqld: Can‘t create/write to file ‘/var/run/mysqld/mysqld.pid‘ (Errcode: 2)
170422 17:39:42 [ERROR] Can‘t start server: can‘t create PID file: No such file or directory
可以看到，无法创建 pid 文件，这肯定是没权限造成的。
/var/run/mysqld 这个路径是配置文件里配的：
[root@SQL-M ~]# tail -3 /etc/my.cnf
[mysqld_safe] log-error=/var/log/mysqld.log pid-file=/var/run/mysqld/mysqld.pid
这里有点奇怪，用 /etc/init.d/mysqld 启动服务时它不会读取配置文件里配置的 pid 路径，而用 mysqld_safe --skip-grant-tables & 忽略授权表方式启动服务却会读取配置文件里的 pid 路径。
不想动 /var/log/ 这个目录的权限，改配置文件
[root@SQL-M ~]# vim /etc/my.cnf
[mysqld_safe] log-error=/var/log/mysqld.log pid-file=/usr/local/mysql/mysqld.pid
[root@SQL-M ~]# /usr/local/mysql/bin/mysqld_safe --skip-grant-tables & # 再次执行
[1] 7109
170422 17:54:17 mysqld_safe Logging to ‘/var/log/mysqld.log‘.
170422 17:54:17 mysqld_safe Starting mysqld daemon with databases from /usr/local/mysql/data
[root@SQL-M ~]# # 这次可以了
[root@SQL-M ~]# mysql # 免密登录
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 1
Server version: 5.5.55-log MySQL Community Server (GPL)
Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type ‘help;‘ or ‘\h‘ for help. Type ‘\c‘ to clear the current input statement.
mysql>
mysql> update mysql.user set password=password(‘123‘) where user=‘root‘ and host=‘localhost‘; # 修改密码
Query OK, 1 row affected (0.00 sec)
Rows matched: 1 Changed: 1 Warnings: 0
mysql> flush privileges;
Query OK, 0 rows affected (0.19 sec)
突然想到 mysqld_safe 这个命令这么厉害，看一下它的权限：
[root@SQL-M ~]# ll /usr/local/sbin/mysqld_safe
-rwxr-xr-x 1 root root 27100 Apr 22 16:39 /usr/local/sbin/mysqld_safe
吓一跳有没有，居然什么人都可以执行，太危险了！
马上改掉，两个地方都改掉：
[root@SQL-M ~]# chmod 700 /usr/local/sbin/mysqld_safe
[root@SQL-M ~]# chmod 700 /usr/local/mysql/bin/mysqld_safe
[root@SQL-M ~]# ll /usr/local/sbin/mysqld_safe
-rwx------ 1 root root 27100 Apr 22 16:39 /usr/local/sbin/mysqld_safe
[root@SQL-M ~]# ll /usr/local/mysql/bin/mysqld_safe
-rwx------ 1 mysql mysql 27100 Mar 18 13:14 /usr/local/mysql/bin/mysqld_safe
以上二进制包简单安装完成。
本文出自 “从没想过放弃！” 博客，请务必保留此出处http://yuyicong.blog.51cto.com/11274530/1918544
标签：mysql
原文地址：http://yuyicong.blog.51cto.com/11274530/1918544
