/etc/my.cnf配置

[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
user=mysql
# Default to using old password format for compatibility with mysql 3.x
# clients (those using the mysqlclient10 compatibility package).
old_passwords=1

# Disabling symbolic-links is recommended to prevent assorted security risks;
# to do so, uncomment this line:
# symbolic-links=0

default-character-set=utf8
default-storage-engine=innodb
# Uncomment the following if you are using InnoDB tables
innodb_data_home_dir = /var/mysql/innodb/
innodb_data_file_path = ibdata1:2000M;ibdata2:10M:autoextend
innodb_log_group_home_dir = /var/mysql/innodb/log/
innodb_log_arch_dir = /var/mysql/innodb/log/

# You can set .._buffer_pool_size up to 50 - 80 %
# of RAM but beware of setting memory usage too high
innodb_buffer_pool_size = 1024M
innodb_additional_mem_pool_size = 20M
# Set .._log_file_size to 25 % of buffer pool size
innodb_log_file_size = 192M
innodb_log_buffer_size = 18M
innodb_flush_log_at_trx_commit = 1
innodb_lock_wait_timeout = 50

[client]
default-character-set=gbk

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

启动mysqld失败，目录权限已设置为777， 并已 /usr/bin/mysql_install_db --user=mysql

原因似乎是innodb的数据目录必须处于datadir配置的子目录下！

查看日志 /var/log/mysqld.log

.........................

120817 13:08:17  InnoDB: Operating system error number 13 in a file operation.
InnoDB: The error means mysqld does not have the access rights to
InnoDB: the directory.
InnoDB: File name /var/mysql/innodb/ibdata1
InnoDB: File operation call: 'create'.
InnoDB: Cannot continue operation.
120817 13:08:17  mysqld ended

修改/etc/my.cnf配置

[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
user=mysql
# Default to using old password format for compatibility with mysql 3.x
# clients (those using the mysqlclient10 compatibility package).
old_passwords=1

# Disabling symbolic-links is recommended to prevent assorted security risks;
# to do so, uncomment this line:
# symbolic-links=0

default-character-set=utf8
default-storage-engine=innodb
# Uncomment the following if you are using InnoDB tables
innodb_data_home_dir=/var/lib/mysql/innodb/
innodb_data_file_path=ibdata1:2000M;ibdata2:10M:autoextend
innodb_log_group_home_dir=/var/lib/mysql/innodb/log/
innodb_log_arch_dir=/var/lib/mysql/innodb/log/
# You can set .._buffer_pool_size up to 50 - 80 %
# of RAM but beware of setting memory usage too high
innodb_buffer_pool_size=1024M
innodb_additional_mem_pool_size=20M
# Set .._log_file_size to 25 % of buffer pool size
innodb_log_file_size=192M
innodb_log_buffer_size=18M
innodb_flush_log_at_trx_commit=1
innodb_lock_wait_timeout=50

[client]
default-character-set=gbk

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

启动成功。