My Time Machine Program thinks it needs 3.5 Tb to back up the computer. I want to limit the backuo my computer's hard drive, because I offload most of my work to external hard drives. It is notwhere near 3.5 Tb.
An incremental backup should require less; and not include other Time Machine backups.
You may try a different USB drive to make new backup that may not show such huge totals.
• If a Time Machine backup takes longer than you expect
• If you see a message that you must create a new backup
Other ways to make non-'Time Machine' backups may be helpful to become familiar with.
Another angle may be to learn to make and use 'full-system clones' on quality external HD.
{.SuperDuper/shirtpocket [&/or] CarbonCopy/bombich: Fine cloner tools. Or use Disk Utility.}
An archive below, can still be useful in most detail, and is near timeless.
Of several works by former contributor & helpful asset to Community:
• Apple OS X and Time Machine Tips | by J. Pond (©2013) archive
http://oldtoad.net/pondini.org/OSX/Home.html
Take care & good luck!🌞⛵️
Seems you'd only need one correct snapshot, & may be able
to use a manual method if restoring bits from T.M. archive.
• About Time Machine local snapshots - Apple Support
https://support.apple.com/en-us/HT204015
Good luck & happy computing!🌻|🐝
Changing the TM program calculation of the size of my backup?
