Why mysql database dont reduce after "clean history selected items"?

[chico]

Hi,
Why mysql database is very large:about 120G, I "clean history selected items" in Configuration-Items, but the database size donot reduce.
What should I do now? I am new to zabbix and mysql.
Thanks!

[nelsonab]

With Innodb as your storage engine for MySQL you will not see the DB files shrink when you clean up the DB. If you however check the DB itself you will see additional space within the DB itself from the space you recently cleared up.

If you wish to physically shrink the DB files themselves you need to perform a mysqldump, erase files, sql import. Do some google searches on resisizing innodb first before proceeding, as you cannot undo this without a good backup, and knowledge of what you are doing.

Hope this helps get you started on your journey.

[chico]

Thanks a lot!

[xs-]

You probably want the option innodb_file_per_table. Requires and dump/restore of the entire db instance tho, but then the data files are shrinkable.