Mac Usb Unable To Unmount Volume For Repair

by admin

Unable to Unmount Volume for repair I have tried booting macOS install from Clover in USB and in internal HDD. I have tried to Use Chameleon bootloader to install Sierra, but it is only booting into Recovery Mode. IBoysoft Data Recovery for Mac is reliable external hard drive data recovery software for Mac users. It is able to recover deleted or lost data from unreadable/unmountable/formatted/corrupted external hard drives. 2015 MacBook Pro unable to enter into recovery mode in order to rest to factory settings. Battery does not work (was recalled) so machine runs severely slow when plugged in. I have pressed co tell R for 15 minutes listening to it ding but it never moves on.

  1. Mac Usb Unable To Unmount Volume For Repair Disk
  2. Mac Usb Unable To Unmount Volume For Repair Cost
  3. Mac Usb Unable To Unmount Volume For Repair Mac

You may get the error 'The disk you inserted was not readable by this computer' when plug in a USB flash drive to your Mac. You can fix the unreadable USB flash drive by formatting, which will erase all your data. It's better recover the unreadable flash drive with iBoysoft Data Recovery for Mac before you fix or format it.

Problem Description - USB flash drives not readable on Mac

As we all know, USB flash drives are widely used for storing and transferring data from an iMac, MacBook or Mac Mini, though newer MacBook Pro and Air uses no USB 3.0 port.

'I have a 32 GB USB which has suddenly come up with a message stating the USB flash drive is not readable by this computer (Apple MacBook Pro). I do not want to initialize it as this will result in loss of my data. How can I fix the unreadable USB on Mac and recover lost data?'

Generally, when you insert in the USB pen drive, it will be mounted in Disk Utility and on Desktop for data access. However, a very distressing situation, just as the user above, is that the USB flash drive may not be readable, recognized, working, or not showing up on Mac.

How to fix unreadable USB flash drive on Mac?

Here are 6 methods to fix your unreadable USB thumb drive and make it working on your Apple Mac again.

Solution 1: Check the USB port or cable

Check that USB port on your Mac. Plug into a different USB port or plug another device in and see if that works OK.

If you use a USB hub bacause your MacBook has no USB 3.0 port, also make sure the hub is not faulty. Try using a different USB cable with the USB drive to see if that fixes the non-readable problem.


Solution 2: Update or reinstall the driver

When your USB flash drive is not readable by your Mac, especially after a recent macOS Big Sur update or you haven't updated the macOS for years, you should check if any updates are available please do the following:

  • 1. Click on the Apple in the upper left corner of the screen.
  • 2. Select 'Software Update...'
  • 3. Any updates available will be listed and able to be downloaded or you will be told your software is up to date.

If not, check the official website of the USB manufacturer for any update.

Solution 3: Check the file system format


If the files system is NTFS format, it's not hard to understand why the USB flash drive is unreadable on Mac. To make sure, you can go to Disk Utility and check its file system. To fix the incompatible issue, you can download and install an NTFS driver to read and write NTFS drives on Mac.

Solution 4: Repair the unreadable USB flash drive with First Aid

You don't have seek for online USB flash drive repair. Instead, Disk Utility's First Aid on your Mac is capable of repairing minor errors of disks.

Here is how to repair USB flash drive when it's not readable, not recognized, not working, or even not showing up on your Mac.

  • 1. Launch Disk Utility from Utilities.
  • 2. Select the unreadable USB drive from the sidebar.
  • 3. Click First Aid at the top of the window, and then wait until the reparation process finishes.

Solution 5: Recover and reformat the unreadable USB drive

Mac usb unable to unmount volume for repair cost

IfFirst Aid failed to fix the unreadable drive, it indicates that the USB drive might have severe errors beyond its capability. Then the best solution is to reformat the unreadable USB drive and make it readable or usable again.

But keep in mind that formatting USB flash drive on Mac will wipe all data stored on it. So, please make sure you have a backup copy out of the USB drive.

If you are unable to do so because you can't open it for backup already, follow the steps to recover lost data from the unreadable USB drive with iBoysoft Data Recovery for Mac.

iBoysoft Data Recovery for Mac is afree USB drive data recovery tool that supports recovering deleted videos, documents, photos, music and much more files from unreadable USB flash drives from Samsung, SanDisk, Toshiba, Lexar, PNY, etc.

Besides, iBoysoft Data Recovery for Mac also recovers deleted files from flash drives, recover lost data from formatted, inaccessible, unmounted, corrupted drives

Steps to recover lost data and fix the unreadable USB drive on Mac

Now, download iBoysoft Data Recovery for Mac on your macOS Big Sur 11/Catalina 10.15/Mojave 10.14/High Sierra 10.13 and older to recover unreadable flash drive.

  • 1. Connect the unreadable USB drive to Mac.
  • 2.Launch iBoysoft Data Recovery for Mac.
  • 3. Select the unreadable USB and click the Next button. The program will start to scan for lost files.
  • 4. Preview the scanning results and choose files you want to recover, and then click Recover button to get those files back.
  • 5. Launch Disk Utility and format the USB flash drive on your Mac.

Hopefully, the USB drive will be readable now.

Solution 6: Send the unreadable USB drive to a local technician

Sometimes, you cannot format the unreadable USB drive when it's bricked. In this case, this USB flash drive is probably damaged physically, and you have to ask a local repair technician for help.


Bonus tips: How to maintain an USB flash drive for usage

Firstly, make sure that your USB flash drives don't become unreadable/corrupted in the future by always properly unmounting the disk properly after using it.

Secondly, download install an anti-virus program and check your computer and USB drive for virus or malware regularly.

Moreover, keep the driver and the Mac computer updated. The last and most important thing is to remember backing up important files as it is the golden rules to avoid data loss.

If unfortunately, you have lost data on your Mac computer or any other storage media, you can rely on iBoysoft Data Recovery for Mac. Just download this program and get all lost data back.

Why is USB flash drive is not readable on Mac?

Actually, USB drives are susceptible to such kind of corruptions, as these drives are usually plugged in and out.

Here are some of the common reasons behind this issue:

  • USB flash drive is virus infected
  • A virus or a Trojan may delete critical system elements, thus disabling the OS and making the drive unrecognized.
  • USB flash drive file system corruption
  • The USB flash drive was removed improperly from the computer for reasons like sudden power surge, abrupt removal, and unintentional touch, which leads to file system corruption.
  • Faulty USB port or cable
  • If the USB port or cable of the computer is not working properly, your Mac computer won't recognize or read the flash drive.
  • File system incompatibility
  • The issues between the USB drive file system and macOS, for example, Windows NTFS file system is not completely compatible with macOS.
  • Sometimes, you can't even read files or folders on NTFS USB drives through an Apple M1 Mac.
  • Out-of-date drivers
  • If drivers are out of date, the Mac operating system and your applications on the computer will fail to interact with all hardware devices. So the USB flash drive becomes unreadable.
  • A dead/bricked USB drive after physical damage
  • If your USB drive is seriously broken by hitting, dropping, shaking, etc., there is no USB repair tool or USB flash recovery software for Mac can help you.


Wish you have fixed the unreadable USB flash drive and now it's working perfectly on your Mac. These effective solutions also can be used when USB not recognized, working, showing up on Mac.

Mac Usb Unable To Unmount Volume For Repair Disk

Which solution really helps you out? Do you have any other great solution to fix this issue? Please don't be hesitate to share them with us.

Macintosh HD, or the MacBook internal hard drive, is basically the startup drive of most Apple computers. That means if your Mac or MacBook Pro can’t mount its startup disk, it is likely that you will experience problems, like your computer gets stuck on the login screen or it does not boot at all. Situations like this can be very annoying, especially if you have critical and important files stored on the “unmountable” hard drive.

Fret not, because we will teach you what to do if your MacBook Pro won’t mount its startup disk. But before we do that, you better have a backup of all your data.

Backup, Backup, Backup!

Before you proceed with fixing the problem, it is best that you back up all your data first. That way, you can easily retrieve or recover your important documents and files in case something goes wrong.

Now, you might be wondering if it is possible to create a backup of your data, especially that your Mac is not even booting. Here’s what you should know: your Mac has a built-in Disk Utility, which can be accessed before startup. To use this, follow the steps below:

  1. Get an external hard drive and connect it to your Mac.
  2. Switch off your Mac. After five seconds, switch it back on.
  3. After hearing the startup sound, press the CMD and R keys. Hold them until the Apple logo appears.
  4. The macOS Utilities window will now appear.
  5. Choose Disk Utility and hit Continue to proceed.
  6. You can now start backing up your data using the external drive. Once you have backed up all your data, you can try a few fixes to your “unmountable” hard drive problems.

4 Fixes to a MacBook Pro That Can’t Mount Its Startup Disk

In most cases, mounting is an automatic process that happens as soon as the hard drive is connected to a Mac or MacBook Pro. Then again, drive mounting can be performed manually using the Disk Utility of your machine. It will be discussed further below.

Going forward, assuming you already have a backup of your important files and data, let’s proceed with resolving the problem. Below are a few ways to fix a MacBook Pro that can’t mount its startup disk:

1. Fix Your Hard Drive.

Sometimes, restarting your Mac is more than enough to fix the problem. However, if that does not work, then you might want to look into the angle that there might be something wrong with your hard drive. If that is the case, you have to boot your MacBook Pro in Recovery Mode via Disk Utility.

To hopefully fix your hard drive, follow these steps:

  1. Switch off your MacBook Pro.
  2. Turn it back on by pressing the Power button. But while doing that, press the CMD and R keys as well until the Apple logo appears.
  3. The macOS Utilities window will open. From there, select Disk Utility.
  4. From the left pane, choose your MacBook Pro hard drive.
  5. Navigate to the First Aid tab.
  6. Click the First Aid button to start fixing your drive.
  7. Wait for the process to finish before restarting your machine.

2. Run Your MacBook Pro in Safe Mode.

When booted in Safe Mode, your MacBook Pro will start only with the minimum requirements and utilities needed. All other programs and apps that are unnecessary will never be loaded. Hence, if the reason why your startup disk cannot be mounted is a faulty app or program, booting your MacBook Pro in Safe Mode might just fix your problem.

To run your MacBook Pro in Safe Mode, do these:

  1. Restart your MacBook Pro.
  2. After you hear the startup sound, press the SHIFT key immediately. Continue holding it until the Apple logo appears.
  3. If your MacBook Pro boots up properly, then uninstall any program or app you suspect is causing the problem.
  4. Restart your machine.

3. Disconnect All External Peripherals.

It is possible that a faulty peripheral connected to your MacBook Pro could be causing your startup disk problems. To verify this, follow the steps below:

  1. Switch off your machine.
  2. Disconnect all external peripherals connected to your MacBook Pro, including printers, external hard drives, USBs, and scanner. You may leave the keyboard and mouse attached in the meantime.
  3. Switch on your Mac. If it boots properly, then one of the peripherals is causing the problem.
  4. Identify the exact cause of the problem by connecting each of the peripherals one by one. Make sure you reboot your MacBook Pro every time you connect a peripheral.

4. Reset the SMC and PRAM.

This may sound like a technical solution, but it isn’t. In fact, resetting the SMC and the PRAM takes only a few seconds.

To reset the PRAM and SMC, follow these instructions:

  1. Reboot your MacBook Pro.
  2. After you hear the startup sound, press the Option, CMD, P, and R keys. Hold them until you hear the second startup tone.
  3. Release the keys. Your PRAM will then be reset.
  4. Restart your MacBook Pro and check if the problem persists.
  5. If resetting the PRAM does not fix the problem, try resetting the SMC. Start by shutting down your MacBook Pro.
  6. Plug your machine into a wall outlet.
  7. Next, press the CTRL, SHIFT, Option, and Power keys for 10 seconds and release them together.
  8. Restart your MacBook Pro and see if it worked.

How to Mount a Startup Disk on MacBook Pro

At this point, you probably want to know how to properly mount a startup disk on your MacBook Pro to avoid problems in the future. Well, mounting a startup disk does not literally suggest physically setting it up with all the wires. It simply means making the startup disk available for your system to perform different read and write operations.

If the startup drive is in good shape, your system Disk Utility should see it. Under the Disk Utility window, select your preferred startup disk. Click on it to mount. By now, your new startup disk should be accessible by your operating system.

Mac Usb Unable To Unmount Volume For Repair Cost

What’s Next?

Now that you know how to deal with your “unmountable” startup disk problem, it’s time that you get your MacBook Pro running fast and smooth by downloading and installing a reliable tool like Outbyte MacRepair. Not only will this tool allow you to conveniently find and fix speed and stability problems, it will also protect your privacy. What more can you ask for from such a powerful tool?

If you know other ways to fix a MacBook Pro that can’t mount its startup disk, please share them with us below. We’re looking forward to hearing from you.

Mac Usb Unable To Unmount Volume For Repair Mac

If you’re running into errors and your system is suspiciously slow, your computer needs some maintenance work. Download Outbyte PC Repair for Windows, Outbyte Antivirus for Windows, or Outbyte MacRepair for macOS to resolve common computer performance issues. Fix computer troubles by downloading the compatible tool for your device.
See more information about Outbyte and uninstall instructions. Please review EULA and Privacy Policy.