Backup archive is much bigger than the domain to archive

Virtualmin’s backup function works great for me except for one peculiar domain.
This domain only contains two wordpress blogs with a total amount of 24 Mo. But each time virtualmin backups this domain, it produces a huge .tar.gz file. By huge, I mean 15 Go two days ago, 18 Go yesterday ans 22 Go today. I don’t understand what can be the issue.
Is there a common explaination to such problem ?


If you go into Edit Virtual Server -> Quotas and Limits for that domain, what are these three things set to:

Home disk space used (including sub-servers) Space used by databases Total disk space used

Thank you.
I actualy found out what the issue was, it had nothing to do with virtualmin, it was the fault of a weird backup plug-in for wordpress.

Great, I’m glad you figured it out!