mysql：无法在 Ubuntu 上正常启动

Question 1

你可能安装了 Ubuntu repos 提供的 mysql 包。我建议你安装mysql-apt-config或者直接从下载 DEB 文件MySQL 下载站点。您将在那里找到最新的 5.6.28 版本，而不是 5.6.27 版本。

一旦您安装了 mysql-community-* 包，您将能够初始化 datadir 并能够在不同的 datadir 上启动 mysqld 的新实例。

sudo /usr/bin/mysql_install_db --defaults-file=/etc/my.cnf --user=mysql

然后像这样启动 mysqld：

sudo /usr/sbin/mysqld --defaults-file=/etc/my.cnf --user=mysql

这是我的示例配置文件：

cat /etc/my.cnf 
[mysqld]
basedir=/usr
datadir=/srv/data
pid-file=/srv/data/mysqld.pid
port=3308
socket=/srv/data/mysql.sock

并证明它正在使用所述数据目录：

mysql> select @@datadir;
+------------+
| @@datadir  |
+------------+
| /srv/data/ |
+------------+
1 row in set (0.00 sec)

编辑：您的 mysql_install_db 错误可能与错误有关#70067。

如果您不想安装任何软件包，您可以快速创建此文件并mysql_install_db再次运行。

cat /usr/share/mysql/my-default.cnf 
# For advice on how to change settings please see
# http://dev.mysql.com/doc/refman/5.6/en/server-configuration-defaults.html
# *** DO NOT EDIT THIS FILE. It's a template which will be copied to the
# *** default location during install, and will be replaced if you
# *** upgrade to a newer version of MySQL.

[mysqld]

# 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

# These are commonly set, remove the # and set as required.
# basedir = .....
# datadir = .....
# port = .....
# server_id = .....
# socket = .....

# 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 

sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES

只需确保使用--用户=mysql并不是--用户=root对于/usr/bin/mysql_install_db或/usr/sbin/mysqld

Answer

你可能安装了 Ubuntu repos 提供的 mysql 包。我建议你安装mysql-apt-config或者直接从下载 DEB 文件MySQL 下载站点。您将在那里找到最新的 5.6.28 版本，而不是 5.6.27 版本。

一旦您安装了 mysql-community-* 包，您将能够初始化 datadir 并能够在不同的 datadir 上启动 mysqld 的新实例。

sudo /usr/bin/mysql_install_db --defaults-file=/etc/my.cnf --user=mysql

然后像这样启动 mysqld：

sudo /usr/sbin/mysqld --defaults-file=/etc/my.cnf --user=mysql

这是我的示例配置文件：

cat /etc/my.cnf 
[mysqld]
basedir=/usr
datadir=/srv/data
pid-file=/srv/data/mysqld.pid
port=3308
socket=/srv/data/mysql.sock

并证明它正在使用所述数据目录：

mysql> select @@datadir;
+------------+
| @@datadir  |
+------------+
| /srv/data/ |
+------------+
1 row in set (0.00 sec)

编辑：您的 mysql_install_db 错误可能与错误有关#70067。

如果您不想安装任何软件包，您可以快速创建此文件并mysql_install_db再次运行。

cat /usr/share/mysql/my-default.cnf 
# For advice on how to change settings please see
# http://dev.mysql.com/doc/refman/5.6/en/server-configuration-defaults.html
# *** DO NOT EDIT THIS FILE. It's a template which will be copied to the
# *** default location during install, and will be replaced if you
# *** upgrade to a newer version of MySQL.

[mysqld]

# 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

# These are commonly set, remove the # and set as required.
# basedir = .....
# datadir = .....
# port = .....
# server_id = .....
# socket = .....

# 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 

sql_mode=NO_ENGINE_SUBSTITUTION,STRICT_TRANS_TABLES

只需确保使用--用户=mysql并不是--用户=root对于/usr/bin/mysql_install_db或/usr/sbin/mysqld

Question 2

问题在于配置。更换此

pid-file=/tmp/tmpWtpvgM/tmp/mysqld.pid
datadir=/tmp/tmpWtpvgM/var
port=3308
tmpdir=/tmp/tmpWtpvgM/tmp
socket=/tmp/tmpWtpvgM/tmp/mysql.soc

和

pid-file=/tmp/tmpWtpvgM/tmp/mysqld.pid
datadir=/tmp/tmpWtpvgM/var
port=3308
tmpdir=/tmp/tmpWtpvgM/tmp
socket=/tmp/tmpWtpvgM/tmp/mysql.sock

Answer

问题在于配置。更换此

pid-file=/tmp/tmpWtpvgM/tmp/mysqld.pid
datadir=/tmp/tmpWtpvgM/var
port=3308
tmpdir=/tmp/tmpWtpvgM/tmp
socket=/tmp/tmpWtpvgM/tmp/mysql.soc

和

pid-file=/tmp/tmpWtpvgM/tmp/mysqld.pid
datadir=/tmp/tmpWtpvgM/var
port=3308
tmpdir=/tmp/tmpWtpvgM/tmp
socket=/tmp/tmpWtpvgM/tmp/mysql.sock

Question 3

MySql 有其预编译位置来查找配置文件和数据。因此，如果您想自定义所有内容，最好的办法是从源代码自行编译 mysql。否则可能会很混乱。

根据您的自定义 my.cnf 文件，您的新 datadir 是datadir=/tmp/tmpWtpvgM/var，我猜它是空的，这就是您收到此错误的原因。

您应该先尝试将 mysql 数据从其默认位置（/var/lib/mysql）移动到您的自定义位置，然后尝试启动 mysql。

或者尝试像这样创建它：

mysql_install_db --user=mysql --basedir=/tmp/tmpWtpvgM --datadir=/tmp/tmpWtpvgM/var

检查并确保适当的目录权限。

检查您收到的警告：One can only use the --user switch if running as root

因此以用户身份运行命令root。

以下是两篇非常相关的帖子：

https://stackoverflow.com/questions/4634163/changing-default-my-cnf-path-in-mysql https://stackoverflow.com/questions/1795176/how-to-change-mysql-data-directory

Answer