this is the complete error log:
[root@xxxxxxxxxxx /]# systemctl status mariadb.service -l
● mariadb.service - MariaDB database server
Loaded: loaded (/usr/lib/systemd/system/mariadb.service; disabled; vendor preset: disabled)
Drop-In: /etc/systemd/system/mariadb.service.d
└─migrated-from-my.cnf-settings.conf
Active: failed (Result: exit-code) since Wed 2016-11-02 14:38:29 AST; 7min ago
Process: 28734 ExecStart=/usr/sbin/mysqld $MYSQLD_OPTS $_WSREP_NEW_CLUSTER $_WSREP_START_POSITION (code=exited, status=1/FAILURE)
Process: 28699 ExecStartPre=/bin/sh -c [ ! -e /usr/bin/galera_recovery ] && VAR= || VAR=`/usr/bin/galera_recovery`; [ $? -eq 0 ] && systemctl set-environment _WSREP_START_POSITION=$VAR || exit 1 (code=exited, status=0/SUCCESS)
Process: 28697 ExecStartPre=/bin/sh -c systemctl unset-environment _WSREP_START_POSITION (code=exited, status=0/SUCCESS)
Main PID: 28734 (code=exited, status=1/FAILURE)
Status: "MariaDB server is down"
Memory: 334.6M
CGroup: /system.slice/mariadb.service
├─ 977 /bin/sh /usr/bin/mysqld_safe --basedir=/usr
└─1445 /usr/libexec/mysqld --basedir=/usr --datadir=/var/lib/mysql --plugin-dir=/usr/lib64/mysql/plugin --log-error=/var/log/mariadb/mariadb.log --pid-file=/var/run/mariadb/mariadb.pid --socket=/var/lib/mysql/mysql.sock
Nov 02 14:38:29 sd-102175 mysqld[28734]: 2016-11-02 14:38:29 140020109994112 [ERROR] InnoDB: Unable to lock ./ibdata1, error: 11
Nov 02 14:38:29 sd-102175 mysqld[28734]: 2016-11-02 14:38:29 140020109994112 [Note] InnoDB: Check that you do not already have another mysqld process using the same InnoDB data or log files.
Nov 02 14:38:29 sd-102175 mysqld[28734]: 2016-11-02 14:38:29 140020109994112 [Note] InnoDB: Unable to open the first data file
Nov 02 14:38:29 sd-102175 mysqld[28734]: 2016-11-02 14:38:29 7f58f8eae880 InnoDB: Operating system error number 11 in a file operation.
Nov 02 14:38:29 sd-102175 mysqld[28734]: InnoDB: Error number 11 means 'Resource temporarily unavailable'.
Nov 02 14:38:29 sd-102175 mysqld[28734]: InnoDB: Some operating system error numbers are described at
Nov 02 14:38:29 sd-102175 systemd[1]: mariadb.service: main process exited, code=exited, status=1/FAILURE
Nov 02 14:38:29 sd-102175 systemd[1]: Failed to start MariaDB database server.
Nov 02 14:38:29 sd-102175 systemd[1]: Unit mariadb.service entered failed state.
Nov 02 14:38:29 sd-102175 systemd[1]: mariadb.service failed.