how to run first aid from recovery mac os sierra

It will remove all errors by writing a new file system on the external hard drive and prepare it as a new and blank disk for use.īefore handling the formatting, you need to make sure you have adequate backups of important files. When the external hard drive has been badly corrupted, formatting will be the last fix. If you see the messages telling you that the First Aid failed, the external hard drive is too corrupted to be fixed by First Aid.įix a corrupted external hard drive by formatting Click on the First Aid button, or right-click the external hard drive and choose First Aid from the options.Select the external hard drive at the left side.Open Disk Utility through Finder and Applications.In this case, you can use it to repair the corrupted external hard disk. Run First Aid to repair the software errorsĭo you know First Aid? It is a small utility in Disk Utility for checking and repairing the minor logic errors on a disk.Reboot the Mac/MacBook to refresh all USB ports.Use another USB port/cable/hub/adapter.Wipe the USB port with a clean and dry towel to get rid of any dust or other material.Make sure the connection is clean and firm. Many times, poor connection will make the Mac/MacBook not recognize the external hard drive. To fix a corrupted external hard drive on Mac, the solutions are categorized into without formatting and by formatting.įix a corrupted external hard drive without formattingįormatting usually is the least wanted solution for fixing the problem, so we gather two fixes without formatting here. The corruption not only happens to external hard drives but also to internal Mac hard drive and other external devices. Consequently, users will be unable to open the external hard drive nor access the files on it. The errors will make the external hard drives failed to be mounted, recognized or read by MacOS.

The errors may resident in the partition table, file system, root directory or large data sectors. Different from hardware damages, a corrupted external hard drive usually results from software errors.

How to run first aid from recovery mac os sierra