安装mysql5.5.20遇到cannot create directory `/var/lib/mysql': Permission denied

[lamp@localhost mysql5.5]$ scripts/mysql_install_db --user=lamp

mkdir: cannot create directory `/var/lib/mysql': Permission denied

chmod: cannot access `/var/lib/mysql': No such file or directory

chown: cannot access `/var/lib/mysql': No such file or directory

Cannot change ownership of the database directories to the 'lamp'

user. Check that you have the necessary permissions and try again.

在linux 系统中mysql配置文件的读取顺序为:

/etc/my.cnf /etc/mysql/my.cnf /usr/local/mysql/etc/my.cnf ~/.my.cnf

估计是优先读取/etc/my.cnf导致的，切换到root用户查看/etc/my.cnf .果然datadir定义的路径和前面报错的路径是一致的。

[root@localhost etc]# more /etc/my.cnf

[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
user=mysql
# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=0

[mysqld_safe]
log-error=/var/log/mysqld.log
pid-file=/var/run/mysqld/mysqld.pid

注释掉这个文件，把/etc/my.cnf改个名

[root@localhost etc]# mv my.cnf my.cnf_bak

重新安装默认的mysql数据库，一切正常

[lamp@localhost mysql5.5]$ scripts/mysql_install_db --user=lamp