Thank you for your reply, I wanted to know if its possible to backup only a portion of the footage recording from the blue iris interface.
2 ways I think may work
1.- Create an auxiliary location recording only the last 7 days, and then backup that up to a secondary location. (that would mean recording twice)
2.- Tell the backup software only to retain the last 7 days of files at the backup location. (no idea what issues may arise from this)
I use BI clone cameras to do a real time backup of my cameras. This is a back up to a NAS. Just limit the size of the storage are so that it has 7 days. The NAS is in another area of the house. Clone cameras if setup correctly use very little CPU.
The most import part of your backup is the 5 minutes before your system is destroyed.