[MySQL/MariaDB] 서버 시작 에러

 

에러 내용

 

root@db-server:~# systemctl status mariadb.service
● mariadb.service - MariaDB 10.5.8 database server
   Loaded: loaded (/lib/systemd/system/mariadb.service; enabled; vendor preset: enabled)
  Drop-In: /etc/systemd/system/mariadb.service.d
           └─migrated-from-my.cnf-settings.conf
   Active: failed (Result: exit-code) since Mon 2021-05-31 11:14:34 KST; 24s ago
     Docs: man:mariadbd(8)
           https://mariadb.com/kb/en/library/systemd/
  Process: 7202 ExecStartPost=/etc/mysql/debian-start (code=exited, status=0/SUCCESS)
  Process: 7199 ExecStartPost=/bin/sh -c systemctl unset-environment _WSREP_START_POSITION (code=exited, status=0/SUCCESS)
  Process: 3655 ExecStart=/usr/sbin/mariadbd $MYSQLD_OPTS $_WSREP_NEW_CLUSTER $_WSREP_START_POSITION (code=exited, status=1/FAILURE)
  Process: 3422 ExecStartPre=/bin/sh -c [ ! -e /usr/bin/galera_recovery ] && VAR= ||   VAR=`cd /usr/bin/..; /usr/bin/galera_recovery`; [ $? -eq 0 ]   && systemctl set-environment _WSREP_START_POSITION=$VAR || exit 1 (code=exited, status=0/SUCCESS)
  Process: 3416 ExecStartPre=/bin/sh -c systemctl unset-environment _WSREP_START_POSITION (code=exited, status=0/SUCCESS)
  Process: 3393 ExecStartPre=/usr/bin/install -m 755 -o mysql -g root -d /var/run/mysqld (code=exited, status=0/SUCCESS)
 Main PID: 3655 (code=exited, status=1/FAILURE)
   Status: "MariaDB server is down"

May 31 11:14:34 db-server mariadbd[3655]: 2021-05-31 11:14:34 0 [ERROR] InnoDB: The innodb_system data file 'ibdata1' must be writable
May 31 11:14:34 db-server mariadbd[3655]: 2021-05-31 11:14:34 0 [ERROR] Plugin 'InnoDB' init function returned error.
May 31 11:14:34 db-server mariadbd[3655]: 2021-05-31 11:14:34 0 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed.
May 31 11:14:34 db-server mariadbd[3655]: 2021-05-31 11:14:34 0 [Note] Plugin 'FEEDBACK' is disabled.
May 31 11:14:34 db-server mariadbd[3655]: 2021-05-31 11:14:34 0 [ERROR] Could not open mysql.plugin table: "Table 'mysql.plugin' doesn't exist". Some plugins may be not loaded
May 31 11:14:34 db-server mariadbd[3655]: 2021-05-31 11:14:34 0 [ERROR] Failed to initialize plugins.
May 31 11:14:34 db-server mariadbd[3655]: 2021-05-31 11:14:34 0 [ERROR] Aborting
May 31 11:14:34 db-server systemd[1]: mariadb.service: Main process exited, code=exited, status=1/FAILURE
May 31 11:14:34 db-server systemd[1]: mariadb.service: Failed with result 'exit-code'.
May 31 11:14:34 db-server systemd[1]: Failed to start MariaDB 10.5.8 database server.

 

 

원인파악

MySQL data 디렉토리를 덮어쓰기 해놓고 service mysql restart를 실행했더니 발생한 에러이다. 이 경우 기존에 data 디렉토리는 소유자가 mysql인데 root 권한으로 덮어쓰기 하는 바람에 소유자가 root로 되어있어서 mysql 서비스에서 접근하지 못하여 발생한 에러이다. 이 경우 mysql이 데이터 폴더에 접근이 불가능하기 떄문에 실제로 data 디렉토리에 mysql 데이터베이스가 있음에도 없다고 에러를 뱉어낸다.

 

해결방안

data 디렉토리의 소유자를 mysql로 변경해준다.

 

# chown -R mysql:mysql /mariadb/data