Monterey mounting every connected drive as read-only

[thenewperson]

2 weeks ago I started having this problem where every external drive I connected to my Mac mounts as read-only, including my time machine drive. I've tried multiple potential solutions (changing permissions in the Get Info window, repairing the drives, erasing the drives) however the only that works (for my time machine drive) is the Terminal command sudo mount -u -w /Volumes/TimeMachine. Unfortunately that's temporary as I have to put it in every time I connect the drive (and even with this command I still can't see my old backups and use the time machine UI). My other drives are formatted ExFAT and this doesn't do anything for them - I have to use terminal commands to manage files on them.

Anyone know any way to fix this issue?

 

[Taz Mangus]

If you boot into Safe Mode do the drives still only mount read-only?

 

[thenewperson]

If you boot into Safe Mode do the drives still only mount read-only?

Yep, still the same. However in Recovery mode they mount as writable (and I can see my old backups on my TM drive)

 

[Taz Mangus]

Yep, still the same. However in Recovery mode they mount as writable (and I can see my old backups on my TM drive)

I think that something might be corrupted on your install. One thing you can try is to install a new copy of Monterey to your internal drive. Don’t do an erase, just install on top of what you already installed. See if that helps.

 

[Slartibart]

just in case - did you check wether resetting the SMC helps? Or if login under a different user auto-mounts the volumes?
Just to clarify: external HFS(+), APFS and FAT32/ExFAT drives mount only via terminal? And file operations on such mounted volumes work only via terminal but not in Finder?
If possible I would check with a powered hub or - if you use one already - removing it and connect drives for testing purposes directly to your Mac (which model? MacOS 12.4?).
Otherwise @Taz Mangus ’s advice above seems sound.

 

[thenewperson]

just in case - did you check wether resetting the SMC helps?

I did check, and unfortunately this doesn't help.

Or if login under a different user auto-mounts the volumes?

The drives mount on a separate (and admin) user account but still as read-only

Just to clarify: external HFS(+), APFS and FAT32/ExFAT drives mount only via terminal? And file operations on such mounted volumes work only via terminal but not in Finder?

All mount as read-only and are visible in the finder. The sudo mount -u -w /Volumes/TimeMachine command works on my APFS-formatted TM drive to make it writable so backups can occur. I haven't tried any HFS+-formatted drives yet. My ExFAT drives also mount as read-only, but the terminal command above does not make them writable. I have to perform write operations on those drives using cp/mv/rm commands in terminal.

If possible I would check with a powered hub or - if you use one already - removing it and connect drives for testing purposes directly to your Mac (which model? MacOS 12.4?).

Hmm, I don't have those on hand so I can't immediately test with them. However I did test the drives on an older High Sierra-equipped MBP and the drives were writable on that, so it seems like it's a Monterey issue on my Mac.

 

[thenewperson]

I think that something might be corrupted on your install. One thing you can try is to install a new copy of Monterey to your internal drive. Don’t do an erase, just install on top of what you already installed. See if that helps.

Yeah I think I'll try that. My only fear is something going wrong and my TM backups are somehow inaccessible (though they show up just fine in Recovery however).

 

[kibepo73]

When your external drive or any storage drive shows up as “Read Only” on your mac, then you might be encountering a very common problem with the hard drive. In such a situation, the user can open and view the files on a drive but cannot copy or move files to the storage drive. The possible reasons for this issue could be:

1. External drive is NTFS formatted
2. Disk permission changed to “Read Only”
3. External drive is corrupted

However, the issue can be fixed using the below DIY methods:

1. Reformat the external drive
2. Change/Ignore permissions on an external drive
3. Repair external drive with disk utility’s first aid

Hope this will help you fix the issue!

 

[thenewperson]

When your external drive or any storage drive shows up as “Read Only” on your mac, then you might be encountering a very common problem with the hard drive. In such a situation, the user can open and view the files on a drive but cannot copy or move files to the storage drive. The possible reasons for this issue could be:

1. External drive is NTFS formatted
2. Disk permission changed to “Read Only”
3. External drive is corrupted

However, the issue can be fixed using the below DIY methods:

1. Reformat the external drive
2. Change/Ignore permissions on an external drive
3. Repair external drive with disk utility’s first aid

Hope this will help you fix the issue!

Unfortunately I've tried all of these and none worked.

 

[thenewperson]

I think that something might be corrupted on your install. One thing you can try is to install a new copy of Monterey to your internal drive. Don’t do an erase, just install on top of what you already installed. See if that helps.

I tried this and for some reason it claims I'm not allowed to downgrade the system (by reinstalling 12.4 on a 12.4 system). Maybe I'll try again when 12.5 is released.

 

[bogdanw]

Usually used to achieve the opposite effect, Disk Arbitrator https://github.com/aburgh/Disk-Arbitrator

 

[thenewperson]

Usually used to achieve the opposite effect, Disk Arbitrator https://github.com/aburgh/Disk-Arbitrator

Do you know how to use it? Can it force mount drives as read-write?

 

[bogdanw]

Do you know how to use it? Can it force mount drives as read-write?

I can’t test for your particular problem, as I don’t have drives that mount as read-only, but you can try to install the app, set it to Mode – Block mounts (prevents macOS from auto-mounting), then mount the volume from the app, deselecting “Mount Options – read-only”. Additionally, you can select the option “no owners”.