MintBackup saves to your /home partition; I believe it's in the roadmap to allow you to choose another destination for it. Right now, what I do is to cut-paste the finished MintBackup archive onto an external media, like another harddrive, a CD or a USB stick. That way it's off my /home, and is available for use when I need it. Does this help?
"Dance without sleeping, I'll dance without fear
Dance without senses, no message I hear
Dance without feeling, I'll dance 'til I'm numb
Dance 'til I think I can overcome" -- Melissa Etheridge