2.36TB backup sounds like a fresh whole new backup.. that would mean it needs to delete the entire old backup.. something is wrong I suggest to even have a backup that large.. it will also take a month.
Check Pondini for over large and backup not being able to be deleted.
Try C4 and D4.. to start with.
Basically it is a total backup of several drives 240gig SSD which has the OS used about 100 gig on it then a 3Tb user account drive which is only about .75 Tb used and a 3Tb Media drive which is about 1.3Tb used Guess I cannot back it all up. Oh by the way only takes about 10-12 hours for backup.. Thanks for trying to answer my question.