Disabling InnoDB on a slave results in slave warnings re: mysql.gtid_slave_pos

If you disable InnoDB (I used skip-innodb and default-storage-engine=MyISAM) in MariaDB (tested on 10.0.21) on a slave, then you will end up with the following warnings in your error log and SHOW SLAVE STATUS:

Unable to load replication GTID slave state from mysql.gtid_slave_pos: Unknown storage engine 'InnoDB'

Even if you delete the existing .frm file, and restart, you will still have the issue.

The only work-around is to create the table as MyISAM. However, you must delete the .frm first, and ensure you're in a clean state. Then re-create the table as follows:

CREATE TABLE `mysql`.`gtid_slave_pos` (

`domain_id` int(10) unsigned NOT NULL,

`sub_id` bigint(20) unsigned NOT NULL,

`server_id` int(10) unsigned NOT NULL,

`seq_no` bigint(20) unsigned NOT NULL,

PRIMARY KEY (`domain_id`,`sub_id`)

) ENGINE=MyISAM DEFAULT CHARSET=utf8 COMMENT='Replication slave GTID state';

Then you must stop/start your slave to clear the error from the output.

If you're not using InnoDB nor GTID, then this should not be a requirement, and should not be in your SHOW SLAVE STATUS.