I tried with two different external hard drives. With both, when I connect them to my MacMini M1 (12.3.1) they are READ ONLY.
Strangely Time Machine manages to complete the backups but I can't write these HDs.
if I connect them to an old iMac i5 I can read and write without problems.
Mac mini, macOS 12.3
A thought: Create a second APFS volume in the APFS container on the Time Machine drive. Yes it will be another volume/file system on the drive but unlike the Time Machine volume it will be read write.
The usual warnings about disk space consumption by multiple APFS volumes on the same container apply.
With the drive connected you would need to open the TM preferences, pick select disk and then use the - sign to remove as a TM drive. Then use disk utilities to erase and format APFS, GUID partition. Then you can use as read and write.
It's your property; you should do as you wish. What we are advocating are best practices proven to be such over time. Nobody has to follow anybody's advice, but then that begs the question, why ask?
TM drives are now read only. TM prefers a dedicated drive for backups. Best not to partition or add your own files to this drive. Monterey requires APFS case sensitive.
I have always written on the time machine hdd. I clearly claim that I was using it to make iPhone backups. How can I avoid this whiteout partition?
even if I remove the connection to time machine the hd remains read only forever!
Thanks everyone for the replies. However, I believe that having a 2TB HD and not being able to use it to put other files inside is so frustrating. I still prefer not use Time Machine anymore.
+1 ! Dedication is THE best practice.
I can't write to external HD formatted in APFS (case-sensitive)
