FAQs about external hard drive not mounting up on Mac Knowledge Base: What does 'Mount' mean on Mac? Why can't mount the external hard drive on Mac? Fix external hard drives not mounting on Mac Dos and Don'ts When External Hard Drive Not Mounting on Mac Recover data from an external hard drive that won't mount Method 6: Use a third-party external disk mounter.Method 5: Format the external hard drive.Method 4: Repair your drive with First Aid.Method 3: Force mount the external hard drive in Disk Utility.Method 2: Check Mac's drive display settings.Method 1: Restart your Mac and reconnect the drive.Quick takeaways for external hard drive not mounting on Mac: Wondering ' why my external hard drives won't mount on Mac'? This post explains the reasons and teaches how to fix this disk problem without losing data. I can't do First Aid as my LaCie external drive does not mount on the MacBook Pro. The main drive is greyed out in Disk Utility and the partition is not showing up. Now after updating, macOS is not mounting this external drive. 'I have a 500 GB LaCie external drive, formatted as macOS Extend journaled on MacBook Pro 2014 and I have been using it to do Time Machine backups. So, it's annoying when you find that your Mac external hard drive not mounting for the error or not recognized by your Mac, just like the user below. Usually, an external hard drive will mount automatically on your Mac once you plug it in, and you can access data on this drive.

Mac says disk is full