#systemctl status mysql.service or systemctl status mysqld.service ->
command not found
#systemctl status mariadb.service ->
command not found
why?
# tail -f /var/log/mysqld.log
/usr/libexec/mysqld[0x7b0c10]
/usr/libexec/mysqld(_Z24ha_initialize_handlertonP13st_plugin_int+0x41)[0x67b271]
/usr/libexec/mysqld[0x58fe78]
/usr/libexec/mysqld(_Z11plugin_initPiPPci+0x928)[0x593a68]
/usr/libexec/mysqld[0x519338]
/usr/libexec/mysqld(_Z11mysqld_mainiPPc+0x3fd)[0x51c5fd]
/lib64/libc.so.6(__libc_start_main+0xfd)[0x3d4d01ed1d]
/usr/libexec/mysqld[0x511c85]
The manual page at
http://dev.mysql.com/doc/mysql/en/crashing.html contains
information that should help you find out what is causing the crash.