I have two external hard drives formatted as APFS. When I connect them to my Mac mini M1 (macOS 12.3.1), they become read-only and I can’t write to them. However, they work fine with full read and write access on my older iMac i5. Why is this happening?
You can try the following two methods.
Method1. Check disk permission settings
Right-click on the external drive and select “Get Info”, then look at the “Sharing & Permissions” section at the bottom.
If you can’t modify the permissions, try using Disk Utility and run First Aid to repair the disk.
Method2. Try remounting the drive as read-write using Terminal
Open Terminal and run the following command.
diskutil list
Find your external drive’s identifier (e.g., /dev/disk2s1), then run.
sudo mount -uw /Volumes/YourDriveName
It’s recommended to back up your data first, then reformat the drive in Disk Utility to APFS (Case-insensitive) or exFAT. If you haven’t backed up your data, you’ll need to use data recovery software to retrieve your important files.
iBoysoft Data Recovery for Mac is a professional data recovery tool that can help recover data from a corrupted disk. If needed, give it a try!