I would like to limit the size of my firebird db. Is it possible?

The system is installed in a PC with limit size for HD (for example I can allocate only 5 GB for Database). How can I limit the file to not encrease more than 5 GB?
Obviuosly I periodically delete record in table to save space, but the only way I found to decrease db size is to export and import it through gbak. I would like to do it without disconnect my application to db?

Any ideas?

Thanks