mariadb 소스 설치후 서비스 실행이 안됩니다.

아래와 같은 메시지가 나오면서 실행이 안되네요. 뭐가 문제일까요

[root@localhost support-files]# systemctl start mysqld.service
Job for mysqld.service failed. See 'systemctl status mysqld.service' and 'journalctl -xn' for details.
[root@localhost support-files]# journalctl -xn
-- Logs begin at 목 2015-07-09 19:06:11 KST, end at 목 2015-07-09 21:24:49 KST. --
 7월 09 21:19:37 localhost.localdomain dbus[556]: [system] Successfully activated service 'org.freedesktop.PackageKit'
 7월 09 21:19:37 localhost.localdomain dbus-daemon[556]: dbus[556]: [system] Successfully activated service 'org.freedesktop.PackageKit'
 7월 09 21:20:01 localhost.localdomain systemd[1]: Starting Session 18 of user root.
-- Subject: Unit session-18.scope has begun with start-up
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
--
-- Unit session-18.scope has begun starting up.
 7월 09 21:20:01 localhost.localdomain systemd[1]: Started Session 18 of user root.
-- Subject: Unit session-18.scope has finished start-up
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
--
-- Unit session-18.scope has finished starting up.
--
-- The start-up result is done.
 7월 09 21:20:01 localhost.localdomain CROND[64225]: (root) CMD (/usr/lib64/sa/sa1 1 1)
 7월 09 21:24:48 localhost.localdomain systemd[1]: Starting LSB: start and stop MySQL...
-- Subject: Unit mysqld.service has begun with start-up
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
--
-- Unit mysqld.service has begun starting up.
 7월 09 21:24:49 localhost.localdomain mysqld[64294]: Starting MySQL. ERROR!
 7월 09 21:24:49 localhost.localdomain systemd[1]: mysqld.service: control process exited, code=exited status=1
 7월 09 21:24:49 localhost.localdomain systemd[1]: Failed to start LSB: start and stop MySQL.
-- Subject: Unit mysqld.service has failed
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
--
-- Unit mysqld.service has failed.
--
-- The result is failed.
 7월 09 21:24:49 localhost.localdomain systemd[1]: Unit mysqld.service entered failed state.
[root@localhost support-files]#