My server accidentally got hard rebooted yesterday and after that the MySQL service isn't starting.
sudo service mysql status
the response was stuck at
mysqld --verbose this is the response I got
200305 12:47:59 [Warning] Using unique option prefix key_buffer instead of key_buffer_size is deprecated and will be removed in a future release. Please use the full name instead. 200305 12:47:59 [Warning] The syntax '--log-slow-queries' is deprecated and will be removed in a future release. Please use '--slow-query-log'/'--slow-query-log-file' instead. 200305 12:47:59 [Note] mysqld (mysqld 5.5.47-0ubuntu0.14.04.1-log) starting as process 2536 ... 200305 12:47:59 [Warning] Can't create test file /var/lib/mysql/ip-172-31-12-215.lower-test 200305 12:47:59 [Warning] Can't create test file /var/lib/mysql/ip-172-31-12-215.lower-test 200305 12:47:59 [Warning] One can only use the --user switch if running as root 200305 12:47:59 [Warning] Using unique option prefix myisam-recover instead of myisam-recover-options is deprecated and will be removed in a future release. Please use the full name instead. 200305 12:47:59 [Note] Plugin 'FEDERATED' is disabled. mysqld: Can't find file: './mysql/plugin.frm' (errno: 13) 200305 12:47:59 [ERROR] Can't open the mysql.plugin table. Please run mysql_upgrade to create it. 200305 12:47:59 InnoDB: The InnoDB memory heap is disabled 200305 12:47:59 InnoDB: Mutexes and rw_locks use GCC atomic builtins 200305 12:47:59 InnoDB: Compressed tables use zlib 1.2.8 200305 12:47:59 InnoDB: Using Linux native AIO 200305 12:47:59 InnoDB: Initializing buffer pool, size = 1.0G 200305 12:47:59 InnoDB: Completed initialization of buffer pool 200305 12:47:59 InnoDB: Operating system error number 13 in a file operation. InnoDB: The error means mysqld does not have the access rights to InnoDB: the directory. InnoDB: File name ./ibdata1 InnoDB: File operation call: 'open'. InnoDB: Cannot continue operation.
Currently I can run mysql in safe mode but I'm not sure if there are any issue's in doing that and since this is in production I can't play around with different solutions which would lead to a longer downtime.