Time Machine backup is over 3 times the size of my hard drive and I cannot backup
I just bought a brand new M1 MBP and put my old i7 up for sale to offset the cost. I wasn't planning on selling the old one so quickly but it just sold and I need to back it up. Problem is Time Machine is telling me it needs 1.7TB to back up my 500GB HD. My backup drive is 1TB. There are no items in my "exclude" list, nor any options that allow me to only backup the current state of my computer.
Is there any way to do a TM backup from the current state of my old machine only? I'm guessing it's trying to copy different states of the data.
I'm on Big Sur.
MacBook Pro 14″, macOS 12.1