The current versions of Monterey deletes data on an external drive when the drive is selected as a back-up. See below.
After back up the disk was locked as Read only. See also below. No padlock to change access to the disk.
This is a new feature. I have been using external hard drives for manual storage offline and as a Time machine backup without issue.
I have a 4TB disk and want to use it for multiple purposes.
Thanks. I have reformatted the drive again and partitioned off a volume for Time Machine. The rest of the drive works fine. All easy when you know what is required.
I guess I have got into odd habits as my old Mac had a 500Gb driveand I have offline and historical back-ups. Don't trust major version changes anymore. My new 14" Mac has 1TB .
Apple has decided that for Monterey using a TimeMachine drive for 12 or 13 other purposes makes no sense. TM locks the drive and makes it TM-ONLY. You can reformat the drive to be multi-purpose data drive, but TM takes complete control.
Not that a backup drive being a data drive as well makes much sense, at least to me.
Time machine locks external drives
