The title is pretty explicit, I just want to disable completely redo logs on MariaDB 5.5. This is more of a testing database that might eventually be used for a small web forum, but I don't care about being able to recover from crashes, all I care about is saving disk space.
Is there a way to completely disable redo logs? What if I set the max size to 0?
The redo logs are required by the InnoDB storage engine. The redo logs provide the 'D' in ACID - durability. You can't set the innodb_log_file_size to 0 as the smallest allowed value is 1MB. Also, the smallest value for innodb_log_files_in_group is 1, so you can't use that either.
You can shut down the MariaDB server and disable InnoDB - use these settings in your .cnf file:
[mysqld]
skip_innodb
default_storage_engine=Aria
Then delete the InnoDB redo log files (by default: ib_logfile0 and ib_logfile1 in your datadir - by default /var/lib/mysql/) and start the MariaDB server again.
Use MyISAM instead of InnoDB. That will take between 1/3 and 1/2 the space. There will be a few differences; read this backwards: http://mysql.rjweb.org/doc.php/myisam2innodb
mariadb does not support this, mysql support this from 8 https://dev.mysql.com/doc/refman/8.0/en/innodb-redo-log.html#innodb-disable-redo-logging
In MariDB you can't disable it, but can limit it to a constant size.
Use innodb_undo_log_truncate = ON.
For more details see this other answer: https://stackoverflow.com/a/72122560/2755656
