Mariadb在CentOS 7开始失败

我在CentOS（CentOS Linux版本7.0.1406）中使用Mariadb（mysql Ver 15.1 Distrib 5.5.40-MariaDB） . 我试图重启Mariadb .

systemctl start mariadb

Job for mariadb.service failed. See 'systemctl status mariadb.service' and 'journalctl -xn' for details.

我按照'systemctl status mariadb.service'的建议检查了：/var/log/mysql-error.log

170523 10:20:10 mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql
170523 10:20:10 [Warning] 'THREAD_CONCURRENCY' is deprecated and will be removed in a future release.
170523 10:20:10 [Warning] Changed limits: max_open_files: 1024  max_connections: 214  table_cache: 400
170523 10:20:10 InnoDB: The InnoDB memory heap is disabled
170523 10:20:10 InnoDB: Mutexes and rw_locks use GCC atomic builtins
170523 10:20:10 InnoDB: Compressed tables use zlib 1.2.7
170523 10:20:10 InnoDB: Using Linux native AIO
170523 10:20:11 InnoDB: Initializing buffer pool, size = 15.6G
170523 10:20:11 InnoDB: Completed initialization of buffer pool
170523 10:20:11 InnoDB: highest supported file format is Barracuda.
170523 10:20:12  InnoDB: Waiting for the background threads to start
170523 10:20:13 Percona XtraDB (http://www.percona.com) 5.5.40-MariaDB-36.1 started; log sequence number 5336723441509
170523 10:20:13 [Note] Plugin 'FEEDBACK' is disabled.
170523 10:20:13 [ERROR] /usr/libexec/mysqld: unknown variable 'extra-lsndir=/var/tmp'
170523 10:20:13 [ERROR] Aborting

170523 10:20:13  InnoDB: Starting shutdown...
170523 10:20:15  InnoDB: Shutdown completed; log sequence number 5336723441509
170523 10:20:15 [Note] /usr/libexec/mysqld: Shutdown complete

170523 10:20:15 mysqld_safe mysqld from pid file /var/lib/mysql/master.compare-prices.repchecker.jp.pid ended
170523 10:21:10 mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql
170523 10:21:10 [Warning] 'THREAD_CONCURRENCY' is deprecated and will be removed in a future release.
170523 10:21:10 [Warning] Changed limits: max_open_files: 1024  max_connections: 214  table_cache: 400
170523 10:21:10 InnoDB: The InnoDB memory heap is disabled
170523 10:21:10 InnoDB: Mutexes and rw_locks use GCC atomic builtins
170523 10:21:10 InnoDB: Compressed tables use zlib 1.2.7
170523 10:21:10 InnoDB: Using Linux native AIO
170523 10:21:10 InnoDB: Initializing buffer pool, size = 15.6G
170523 10:21:11 InnoDB: Completed initialization of buffer pool
170523 10:21:11 InnoDB: highest supported file format is Barracuda.
170523 10:21:12  InnoDB: Waiting for the background threads to start
170523 10:21:13 Percona XtraDB (http://www.percona.com) 5.5.40-MariaDB-36.1 started; log sequence number 5336723441509
170523 10:21:13 [Note] Plugin 'FEEDBACK' is disabled.
170523 10:21:13 [ERROR] /usr/libexec/mysqld: unknown variable 'extra-lsndir=/var/tmp'
170523 10:21:13 [ERROR] Aborting
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PS：/ var / lib / mysql目录由mysql拥有（还有一个目录mysql~这是空的）

drwxr-xr-x 8 mysql mysql 4096 5月23日11:05 mysql drwxr-xr-x . 3 mysql mysql 2015年2月26日mysql~

请提供一些建议 . 如何重启我的mariadb，我在mariadb下有重要的数据库 .