Fix Guide: Sequoia External Drive Read-Only Error

Symptom: You connect an APFS or ExFAT drive to macOS Sequoia, and it mounts as "Read Only," even if the permissions are set correctly.

Why this happens

Sequoia has stricter "System Integrity" checks for external volumes. If the drive wasn't ejected properly, the 'fsck' (file system check) flag may lock the volume to prevent data loss.

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Fix 1: Force Unmount and Repair

1. Open Terminal.
2. Find your drive's identifier:

diskutil list

1. Run the repair (replace disk4s1 with your ID):

sudo diskutil repairVolume /dev/disk4s1

Fix 2: Clear Disk Arbitration Cache

1. In Terminal:

sudo killall diskarbitrationd

1. Re-plug your drive.

Recommended Tool: Paragon NTFS for Mac

If you frequently work with Windows-formatted drives:

- Get Paragon NTFS to ensure seamless read/write access on macOS without the stability issues of native experimental drivers.