The disk formatting might be corrupt or unsupported by the Mac, preventing it from mounting properly. However, a failure to mount is sometimes for a good reason. Mounting is the last step between you and your data. It’s possible for a drive to be connected to your Mac and for the operating system to notice the drive but not mount it. Related: Understanding macOS Sierra’s Purgeable Space and How to Use It to Optimize Your Hard Drive Space Check Disk Utilityĭisk Utility will list drives both mounted and unmounted. If possible, use good, known hardware, like a USB cable that you recently used to successfully connect a device previously. If there’s a light on the drive, is it turning on? If it’s a spinning disk, do you feel the drive spinning through the hard drive’s case? Try a different port and different cable to confirm that these are not issues. Most problems with drives on a Mac are caused by a poor connection, so the first step to troubleshooting the problem is to ensure your drive is actually connected to your Mac properly. If you are facing this issue, here are some fixes for you. If you always connect your external hard drive to Mac to run Time Machine backupa, there are times where you will notice that the external hard drive doesn’t show up in your Mac.
