在Mac OS X v10.6 (Snow Leopard)上，启动MySQL会出现以下错误:
服务器退出，没有更新PID文件
文件my.cnf
[mysqld]
port = 3306
socket = /tmp/mysql.sock
skip-external-locking
key_buffer_size = 16K
pid-file=/var/run/mysqld/mysqld.pid
[mysqld_safe]
log-error=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid
当前回答
在我的Homebrew MySQL安装中，我只需要将位于/usr/local/var/mysql/中的ib_logfile0和ib_logfile1移动到另一个目录。
然后我就用mysql了。服务器启动，一切正常。
其他回答
在/etc/ SELinux /config:
SELINUX=禁用并重新启动服务器。
我也有同样的问题。原因很简单。我安装了两个MySQL服务器。一个来自MacPorts，另一个来自下载的包。所以我只是按照这里的说明，从包中卸载了一个。
如何从Mac OS X上卸载MySQL ?
在那之后，MySQL运行得很好。
在我的例子中，当我试图启动MySQL时，我收到了同样的错误:服务器退出而没有更新PID文件。这是我所做的修复(使用终端):
goto /usr/local/var/mysql
sudo rm -rf hostname.err # Delete .err file
cd /usr/local/mysql/support-files
sudo mysql.server start # Success!
对我来说，我必须重新安装MySQL:
brew reinstall mysql
然后按下面的命令启动MySQL，在登录时重新启动:
brew services start mysql
对我来说，解决方案是覆盖/纠正/etc/my/cnf中的数据目录
我用自述文件中提供的说明从源代码构建MySQL 5.5.27:
# Preconfiguration setup
shell> groupadd mysql
shell> useradd -r -g mysql mysql
# Beginning of source-build specific instructions
shell> tar zxvf mysql-VERSION.tar.gz
shell> cd mysql-VERSION
shell> cmake .
shell> make
shell> make install
# End of source-build specific instructions
# Postinstallation setup
shell> cd /usr/local/mysql
shell> chown -R mysql .
shell> chgrp -R mysql .
shell> scripts/mysql_install_db --user=mysql
shell> chown -R root .
shell> chown -R mysql data
# Next command is optional
shell> cp support-files/my-medium.cnf /etc/my.cnf
shell> bin/mysqld_safe --user=mysql &
# Next command is optional
shell> cp support-files/mysql.server /etc/init.d/mysql.server
Mysqld_safe在没有解释的情况下自行终止。运行/etc/init.d/mysql.服务器启动导致错误:
服务器退出没有更新PID文件
I noticed something odd in the installation instructions though. It has ownership changed to mysql for the directory "data", but not to "var"; this is unusual because for years I have had to ensure that var directory was mysql writable. So I manually ran chown -R mysql /usr/local/mysql/var and then attempted to start it again. Still no luck. But worse, no .err file in the var dir - it was in the "data" dir! so scripts/mysql_install_db sets up camp in /usr/local/mysql/var, but the rest of the application seems to want to do its work in /usr/local/mysql/data!
所以我只是编辑了/etc/my.cnf，在部分[mysqld]下，我添加了一个指令，显式地将mysql的数据目录指向var(因为我通常期望它是任何方式)，这样做之后，mysqld启动得很好。add指令看起来像这样:
数据= /usr/地方/mysql/var
为我工作。希望对你有所帮助。
