service mysqld start给了我：
Starting mysqld (via systemctl): Job failed. See system logs and 'systemctl status' for details. [FAILED]
错误日志说：
110913 05:50:44 mysqld_safe Starting mysqld daemon with databases from /home/mysql/prod 110913 5:50:44 [Warning] Can't create test file /home/mysql/prod/myhostname.lower-test 110913 5:50:44 [Warning] Can't create test file /home/mysql/prod/myhostname.lower-test 110913 5:50:44 [Note] Plugin 'FEDERATED' is disabled. 110913 5:50:44 InnoDB: The InnoDB memory heap is disabled 110913 5:50:44 InnoDB: Mutexes and rw_locks use GCC atomic builtins 110913 5:50:44 InnoDB: Compressed tables use zlib 1.2.5 110913 5:50:44 InnoDB: Using Linux native AIO 110913 5:50:44 InnoDB: Initializing buffer pool, size = 16.0M 110913 5:50:44 InnoDB: Completed initialization of buffer pool 110913 5:50:44 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 /home/mysql/prod/ibdata1 InnoDB: File operation call: 'open'. InnoDB: Cannot continue operation. 110913 05:50:44 mysqld_safe mysqld from pid file /var/run/mysqld/mysqld.pid ended
哦，错误13，所以这是一个权限问题，对不对？
chown -R mysql:mysql /home/mysql/prod
仍然不会开始…让我们试试这个：
/usr/libexec/mysqld --console --log-warnings --basedir=/usr --datadir=/home/mysql/prod --user=mysql --pid-file=/var/run/mysqld/mysqld.pid --socket=/var/lib/mysql/mysql.sock
好吧，以便开始正常（我可以使用mysql -u root -plogin），但我甚至不知道这是做什么，它当然不是由systemctlpipe理..让我们确保mysql是一个用户：
# grep 'mysql' /etc/passwd mysql:stuff:stuff:MySQL Server:/var/lib/mysql:/bin/bash
我my.cnf，有点缩写（我已经尝试了以下几个变化）：
[client] #password = your_password port = 3306 socket = /var/lib/mysql/mysql.sock [mysqld] user = mysql port = 3306 basedir = /usr log_warnings = 1 datadir = /home/mysql/prod socket = /var/lib/mysql/mysql.sock log-error = /var/log/mysql.log innodb_data_home_dir = /home/mysql/prod innodb_data_file_path = ibdata1:10M:autoextend #innodb_doublewrite = on #innodb_log_group_home_dir = /home/mysql/prod
我有点在这里亏本..谁能给我一条线？
# ls -lah / | grep 'home' drwxr-xr-x. 6 root root 4.0K Aug 15 12:20 home # ls -lah /home | grep 'mysql' drwxr-xr-x. 6 mysql mysql 4.0K Sep 8 06:14 mysql # ls -lah /home/mysql/prod drwxr-x---. 2 mysql mysql 4.0K Sep 14 2009 bugs -rw-r--r--. 1 mysql mysql 18M Sep 13 06:17 ibdata1 -rw-r--r--. 1 mysql mysql 5.0M Sep 13 06:17 ib_logfile0 -rw-r--r--. 1 mysql mysql 5.0M Sep 13 05:23 ib_logfile1
（删除了一些隐私的东西）
如果你使用SELinux（Fedora，SUSE，某些Ubuntu），那可能是问题所在。 你需要改变你的安全上下文为mySQL类似于：
chcon -Rv --type=mysqld_db_t /my/new/data/dir
或者如果您使用的是AppArmor（Ubuntu），则需要更新
/etc/apparmor.d/usr.sbin.mysql