Using Archive or Purge options for SRM retention policy does not appear to be reclaiming disk space. How do I get that disk space back?
This is because of how MySQL handles disk space and how it allocates it. The issue is that once MySQL has allocated disk space it will remain that size until the table is optimized.
To optimized the tables and gain the disk space
If you see any errors like this:"The storage engine for the table doesn't support optimize", it can be safely ignored. When complete, verify disk space has been regained.