Reformatting external drive to APFS Case Sensitive despite user's choice of APFS Encrypted

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Level 1

14 points

Reformatting external drive to APFS Case Sensitive despite user's choice of APFS Encrypted

A really odd one guys. I have just purchased an Air, together with a new external drive. I reformatted the drive to APFS Encrypted and set it as back-up for my Air. I then noticed that I was unable to drag/drop folders onto the external drive. Did some research; most people saying it was a reformatting issue! So, went into Utilities and checked my formatting. Couldn't believe it. My reformatting informed me that I had not reformatted to APFS Encrypted, but APFS Case Sensitive. No way. I'm always careful when re-formatting. So, I erased the disk again and set it firmly to APFS Encrypted. Bingo, could drag and drop everything fine ... Until I set it to back-up my Air. It appears Apple does not wish you to encrypt an external drive because the same thing happened again. Couldn't drag/drop anything. So, once again went into Utilities and found it had been set to APFS Case Sensitive. To find each time - and I did this no less than 3 times, taking screen shots each step of the way - Apple is reformatting my external drive to prevent me from drag/dropping items and cancelling out the encryption I set is going a step too far. If anyone has any ideas, please spill

[Edited by Moderator]

Original Title: APPLE REFORMATTING TO UNACCEPTABLE FORMAT

MacBook Air (M4, 2025)

Posted on Aug 18, 2025 2:11 PM

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Answer 1

Aug 18, 2025 2:43 PM in response to P0ppey

The current Time Machine process sets a TM backup volume as “read only”. If you wish to use an external drive as a TM backup drive AND maintain the ability to manually copy files to that external drive, then you should use the (any) APFS format and add a second APFS volume to the drive. With that done you can use one volume for TM and the other for your manual files.

FYI - it’s never a good idea to share a backup device with general file storage. When the drive fails you’ll lose all.

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Answer 2

Aug 19, 2025 8:50 AM in response to P0ppey

It's never been a good idea to use a single disk for both Time Machine backups and general file storage. If you want to accomplish that goal, you need to set up multiple partitions/volumes on the disk and dedicate one for TM.

That's what I've done with my NAS, for example – 6 volumes, one for file storage and 5 for TM backups of the 5 Macs in the house.

I agree with @D.I. Johnson in general about not putting all the eggs in one basket, in my case there are 4 baskets (the NAS is RAID1 meaning everything is on two separate HDDs, and I also back up to a pair of SSDs with one stored offsite, and with a separate pair of SSD for general files also stored offsite).

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Answer 3

P0ppey Author

Level 1

14 points

Aug 19, 2025 6:07 AM in response to D.I. Johnson

Thank you for coming back with the advice; I would not have thought of it to be honest. I sometimes feel that new technology is taking us backwards instead of forwards as I used to just be able to plug and go, now I have to to create another volume to do the same thing.

Once again, many thanks.

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Answer 4

Aug 19, 2025 9:23 AM in response to P0ppey

You’re welcome.

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Reformatting external drive to APFS Case Sensitive despite user's choice of APFS Encrypted

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