Failed to start (MySQL)

Het probleem

$ sudo service mysql restart
mysql stop/waiting
start: Job failed to start

Log files

Begin hier:

less /var/log/mysql/error.log

Tijdens een storing in januari 2016, stond dit in het logboek:

160101  1:24:31 [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.
160101  1:24:31 [Note] Plugin 'FEDERATED' is disabled.
160101  1:24:31 InnoDB: The InnoDB memory heap is disabled
160101  1:24:31 InnoDB: Mutexes and rw_locks use GCC atomic builtins
160101  1:24:31 InnoDB: Compressed tables use zlib 1.2.3.4
160101  1:24:31 InnoDB: Initializing buffer pool, size = 4.0G
InnoDB: mmap(4395630592 bytes) failed; errno 12
160101  1:24:31 InnoDB: Completed initialization of buffer pool
160101  1:24:31 InnoDB: Fatal error: cannot allocate memory for the buffer pool
160101  1:24:31 [ERROR] Plugin 'InnoDB' init function returned error.
160101  1:24:31 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed.
160101  1:24:31 [ERROR] Unknown/unsupported storage engine: InnoDB
160101  1:24:31 [ERROR] Aborting

Oftewel: InnoDB had een geheugen-allocatieprobleem en weigerde te starten.

Oplossing

Deze aanpassing in /etc/mysql/my.cnf:

# innodb_buffer_pool_size = 4G  # Gaf foutmelding
innodb_buffer_pool_size = 1G

et voilà:

$ sudo service mysql start
mysql start/running, process 8202