How to fix external hard drive unreadable/unmountable after unplugging?

Posted by Katrina to Mac Data Recovery on April 28th, 2018

After accidentally ejecting the wrong drive, I stupidly pulled the USB cord connecting the external hard drive. Then whenever I plugged in the external hard drive, my Mac computer claimed that: "The Disk you inserted was not readable by this computer". When I checked in Disk Utility, I found the external hard drive unmountable. Can anyone tell me how to fix external hard drive unreadable/unmountable after unplugging?

We are always reminded to safely ejecting external hard drives as accidental unplugging may result in data loss, corrupted file system, crashing programs and an unbootable computer. However, we still can't avoid unexpected situations, just like the above example. If you are upset by the unreadable/unmountable external hard drive after unplugging, this page will show you how to recover data from unreadable and unmountable external hard drives.

How to fix external hard drive unreadable/unmountable after unplugging?

Even though after accidental unplugging, the external hard drive is unreadable/unmountable and likely to cause data loss, there are still some ways to recover data from the unreadable and unmountable external hard drives.

Solution 1: Repair unreadable/unmountable external hard drive after unplugging via Disk Utility

First Aid is a built-in tool in Disk Utility to check and repair disk errors on Mac. Any logical problem on hard disk could probably be solved by First Aid in Disk Utility.

Step 1: Launch Disk Utility.

Step 2: Choose the unreadable/unmountable external hard drive.

Step 3: Select First Aid in the top center and click Run.

Solution 2: Fix unreadable/unmountable external hard drive after unplugging by reformatting

Since the unreadable/unmountable external hard drive after plugging is result from corrupted file system, reformatting is able to fix it. But reformatting will erase all data on your external hard drive. Therefore, if those files are important to you, you should firstly recover data from the unreadable/unmountable external hard drive with professional data recovery software, like iBoysoft Mac Data Recovery and then reformat this external hard drive.

iBoysoft Mac Data Recovery is free Mac data recovery program that recover data from unreadable/unmountable external hard drives after unplugging, recover data from formatted external hard drives, recover data from unmountable external hard drives, recover data from inaccessible external hard drives, recover data from corrupted external hard drives, recover files deleted or lost from external hard drive, etc. on Mac.

iBoysoft Mac Data Recovery can recover deleted/lost documents, pictures, videos, emails on external hard drive, hard drive, USB flash drive, SD card, memory card and other storage devices. It's supports file systems: encrypted APFS, HFS+, HFS, FAT32 and exFAT.

Step 1: Recover data from unmountable/unreadable external hard drive with iBoysoft Mac Data Recovery

1. Download and install iBoysoft Mac Data Recovery on Mac.

2. Launch iBoysoft Mac Data Recovery.

Recover data from unreadable/unmountable external hard drive after plugging

3. Select the unreadable/unmountable external hard drive and click "Next" button to scan all lost data.

4. Preview the searching results, choose files we need, and click "Recover" to get them back.

Step 2: Reformat the unreadable/unmountable external hard drive

1. Launch Disk Utility.

2. Select the unmountable external hard drive on the left part of the window.

3. Click the Erase on the top of the Disk Utility window.

4. Complete the related information (name, format, scheme), then click Erase.

After reformatting, the unreadable/unmountable external hard drive after unplugging will be usable again.

Why is the external hard drive unreadable/unmountable after unplugging?

External hard drives could become unreadable/unmountable after accidental unplugging, which can cause data loss. It is because most operating systems use the write caching that they don't always write a file to a drive immediately. Instead, they will cache and wait until there are multiple write operations to complete. If exchange of data from external hard drive to computer is suddenly cut off when the cache is full, your data along with the file system will become corrupted.

In this situation, the external hard drive will be unmountable/unreadable after accidental unplugging.

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