my.cnf已经存在，影响安装--mysql，my.cnf--mysql
Found existing config file ./my.cnf on the system.
Because this file might be in use, it was not replaced,
but was used in bootstrap (unless you used --defaults-file)
and when you later start the server.
The new default config file was created as ./my-new.cnf
以上提示是在运行了
scripts/mysql_install_db --user=mysql
之后提示的，这是因为我的/usr/local/mysql/下已经有了my.cnf，将其改名，再重试，就ok了
可以的。但是要设置mysql访问权限。
配置文件还是一个，只不过mysql的数据库存放目录需要多个，这根据你的实例来配置数据库存放目录。
给个多实例配置案例：
初始化数据库
[mysql@localhost ~]$ mkdir /mydata/mysql_db/data_1001 #创建数据库存放目录
[mysql@localhost ~]$ mkdir /mydata/mysql_db/data_1002
[mysql@localhost ~]$ mkdir /mydata/mysql_db/data_1003
[mysql@localhost mysql_db]$ ./bin/mysql_install_db –basedir=/mydata/mysql_db –datadir=/mydata/mysql_db/data_1001 –user=mysql #数据库初始化
Installing MySQL system tables…
OK
Filling help tables…
OK
To start mysqld at boot time you have to copy
support-files/mysql.server to the right place for your system
PLEASE REMEMBER TO SET A PASSWORD FOR THE MySQL root USER !
To do so, start the server, then issue the following commands:
/mydata/mysql_db/bin/mysqladmin -u root password ‘new-password’
/mydata/mysql_db/bin/mysqladmin -u root -h localhost password ‘new-password’
Alternatively you can run:
/mydata/mysql_db/bin/mysql_secure_installation
which will also give you the option of removing the test
databases and anonymous user created by default. This is
strongly recommended for production servers.
See the manual for more instructions.
You can start the MySQL daemon with:
cd /mydata/mysql_db ; /mydata/mysql_db/bin/mysqld_safe &
You can test the MySQL daemon with mysql-test-run.pl
cd /mydata/mysql_db/mysql-test ; perl mysql-test-run.pl
Please report any problems with the /mydata/mysql_db&......余下全文>>