linux安装mysql5.7步骤及无法登录解决方法

linux安装mysql

以下是我在linux上安装mysql5.7版本的步骤以及遇到的一些问题的解决办法

安装步骤

1. 如下为mysql下载地址：https://dev.mysql.com/downloads/mysql/5.7.html#downloads
   

2. 在根目录下创建文件夹software和数据库数据文件/data/mysql

mkdir /software/
mkdir /data/mysql

3. 上传mysql-5.7.26-linux-glibc2.12-x86_64.tar.gz文件到/software下

4. 对文件进行解压

cd /software/
tar -zxvf mysql-5.7.26-linux-glibc2.12-x86_64.tar.gz

5. 更改解压缩后的文件夹名称

mv /software/mysql-5.7.26-linux-glibc2.12-x86_64.tar.gz/ /software/mysql

6. 创建mysql用户组和mysql用户

groupadd mysql
useradd -r -g mysql mysql

7. 关联myql用户到mysql用户组中

chown -R mysql:mysql /software/mysql/
chown -R mysql:mysql /data/mysql/
chown -R mysql /software/mysql/
chown -R mysql /data/mysql

8. 更改mysql安装文件夹mysql/的权限

chmod -R 755 /software/mysql/

9. 安装libaio依赖包，后面mysql的安装过程中需要用到这个库
   查询是否暗转libaio依赖包

yum search libaio
如果没安装，可以用下面命令安装
yum install libaio

10. 初始化mysql命令

cd /software/mysql/bin
./mysqld --user=mysql --basedir=/software/mysql --datadir=/data/mysql --initialize
在执行上面命令时特别要注意一行内容
[Note] A temporary password is generated for root@localhost: o*s#gqh)F4Ck
root@localhost: 后面跟的是mysql数据库登录的临时密码，每个人安装生成的临时密码不一样
如果初始化时报错如下：
error while loading shared libraries: libnuma.so.1: cannot open shared objec
是因为libnuma安装的是32位，我们这里需要64位的，执行下面语句就可以解决
yum install numactl.x86_64
执行完后重新初始化mysql命令

11. 启动mysql服务
    #sh /software/mysql/support-files/mysql.server start
    上面启动mysql服务命令是会报错的，因为没有修改mysql的配置文件，报错内容大致如下：
    ./support-files/mysql.server: line 239: my_print_defaults: command not found
    ./support-files/mysql.server: line 259: cd: /usr/local/mysql: No such file or directory
    Starting MySQL ERROR! Couldn’t find MySQL server (/usr/local/mysql/bin/mysqld_safe)

12. 修改Mysql配置文件
    #vim /software/mysql/support-files/mysql.server
    修改前

   if test -z “$basedir”
   then
   basedir=/usr/local/mysql
   bindir=/usr/local/mysql/bin
   if test -z “$datadir”
   then
   datadir=/usr/local/mysql/data
   fi
   sbindir=/usr/local/mysql/bin
   libexecdir=/usr/local/mysql/bin
   else
   bindir="$basedir/bin"
   if test -z “$datadir”
   then
   datadir="$basedir/data"
   fi
   sbindir="$basedir/sbin"
   libexecdir="$basedir/libexec"
   fi
修改后

   if test -z “$basedir”
   then
   basedir=/software/mysql
   bindir=/software/mysql/bin
   if test -z “$datadir”
   then
   datadir=/data/mysql
   fi
   sbindir=/software/mysql/bin
   libexecdir=/software/mysql/bin
   else
   bindir="$basedir/bin"
   if test -z “$datadir”
   then
   datadir="$basedir/data"
   fi
   sbindir="$basedir/sbin"
   libexecdir="$basedir/libexec"
   fi
保存退出
#cp /software/mysql/support-files/mysql.server /etc/init.d/mysqld
#chmod 755 /etc/init.d/mysqld
13. 修改my.cnf文件
#vi /etc/my.cnf
将下面内容复制替换当前的my.cnf文件中的内容

   [client]
   no-beep
   socket =/software/mysql/mysql.sock
   #pipe
   #socket=0.0
   port=3306
   [mysql]
   default-character-set=utf8
   [mysqld]
   basedir=/software/mysql
   datadir=/data/mysql
   port=3306
   pid-file=/software/mysql/mysqld.pid
   #skip-grant-tables
   skip-name-resolve
   socket = /software/mysql/mysql.sock
   character-set-server=utf8
   default-storage-engine=INNODB
   explicit_defaults_for_timestamp = true
   #Server Id.
   server-id=1
   max_connections=2000
   query_cache_size=0
   table_open_cache=2000
   tmp_table_size=246M
   thread_cache_size=300
   #限定用于每个数据库线程的栈大小。默认设置足以满足大多数应用
   thread_stack = 192k
   key_buffer_size=512M
   read_buffer_size=4M
   read_rnd_buffer_size=32M
   innodb_data_home_dir = /data/mysql
   innodb_flush_log_at_trx_commit=0
   innodb_log_buffer_size=16M
   innodb_buffer_pool_size=256M
   innodb_log_file_size=128M
   innodb_thread_concurrency=128
   innodb_autoextend_increment=1000
   innodb_buffer_pool_instances=8
   innodb_concurrency_tickets=5000
   innodb_old_blocks_time=1000
   innodb_open_files=300
   innodb_stats_on_metadata=0
   innodb_file_per_table=1
   innodb_checksum_algorithm=0
   back_log=80
   flush_time=0
   join_buffer_size=128M
   max_allowed_packet=1024M
   max_connect_errors=2000
   open_files_limit=4161
   query_cache_type=0
   sort_buffer_size=32M
   table_definition_cache=1400
   binlog_row_event_max_size=8K
   sync_master_info=10000
   sync_relay_log=10000
   sync_relay_log_info=10000
   #批量插入数据缓存大小，可以有效提高插入效率，默认为8M
   bulk_insert_buffer_size = 64M
   interactive_timeout = 120
   wait_timeout = 120
   log-bin-trust-function-creators=1
   sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES

   #
   #include all files from the config directory
   #
   !includedir /etc/my.cnf.d
保存退出

14. 启动mysql

/etc/init.d/mysqld start

新版本的安装包会报错，错误内容如下：

Starting MySQL.Logging to ‘/data/mysql/SZY.err’.
2018-07-02T10:09:03.779928Z mysqld_safe The file /usr/local/mysql/bin/mysqld
does not exist or is not executable. Please cd to the mysql installation
directory and restart this script from there as follows:
./bin/mysqld_safe&
See http://dev.mysql.com/doc/mysql/en/mysqld-safe.html for more information
ERROR! The server quit without updating PID file (/software/mysql/mysqld.pid).
因为新版本的mysql安全启动安装包只认/usr/local/mysql这个路径。
解决办法：
方法1、建立软连接
例 #cd /usr/local/mysql

ln -s /sofware/mysql/bin/myslqd mysqld

方法2、修改mysqld_safe文件（有强迫症的同学建议这种，我用的这种）

vim /software/mysql/bin/mysqld_safe
将所有的/usr/local/mysql改为/software/mysql
保存退出。（可以将这个文件拷出来再修改然后替换）

15. 登录mysql
    输入临时密码。临时密码就是步骤10中root@localhost:后面的内容
16. 修改mysql的登录密码

mysql set password=password(‘root’);
mysql grant all privileges on . to root@’%’ identified by ‘root’;
mysql flush privileges;

17. 完成，此时mysql的登录名root 登录密码root

默认密码无法登录解决

如果使用临时密码登录不上。可以尝试修改配置文件，使其无密码登录，步骤如下：

1. 修改/etc/my.cnf文件，在最后一行加上 skip-grant-tables #忽略mysql权限问题，直接登陆
2. service mysqld stop 关闭mysql服务
3. 重启mysql服务 /software/support-files/mysql.server start
4. 此时再使用命令 /software/mysql/bin/mysql -uroot -p 进行登录 ，不需要输入密码直接回车
5. 然后选择数据库： use mysql;
6. update user set authentication_string=password(‘123456’) where user=‘root’ and host=‘localhost’;
   这样就可以修改root用户的密码为 123456
7. 当再次登录的时候报错：ERROR 1820 (HY000): You must reset your password using ALTER USER statement before executing this statement. 时，再次修改密码：
   SET PASSWORD = PASSWORD(‘123456’);
   ALTER USER ‘root’@‘localhost’ PASSWORD EXPIRE NEVER;
   flush privileges;
   此时在linux就可以正常操作了
8. 但是此时使用windows的navicat登录数据库时，会发现还是无法连接上，需要修改host:
   update user set host = ‘%’ where user =‘root’;
   flush privileges;
   此时就可以使用navicat连接linux的数据库了