15 Worst Mac Hard Drive Problems with Solutions

  • Vishal

    Written By Vishal linkdin

  • Rohit Arora

    Approved By Rohit Arora linkdin

  • Updated on

    Updated on February 15, 2021

  • Min Reading

    Min Reading 11 Min

Summary: In this blog, we’ll share the 15 worst Mac hard drive problems with their solutions. The mentioned problems are generic and occurs frequently on one's MacBook Pro, Air, iMac, Mini or Mac Pro. Besides, download data recovery software for free to recover your data from a Mac hard drive.

15 Worst Mac Hard Drive Problems with Solutions
Table of Content

1. Mac hard drive is running slow
2. Mac hard drive space is disappearing
3. Mac hard drive is not showing up in Disk Utility
4. Disk Utility can’t repair Mac hard drive
5. Mac external hard drive is not mounting or is unrecognized
6. Mac hard drive data is lost permanently
7. Mac hard drive’s partition is deleted
8. Mac hard drive is not booting
9. Mac hard drive is making a clicking noise
10. Mac hard drive is not detected in Windows
11. Unable to partition Mac hard drive
12. Bad sectors in Mac hard drive
13. Mac hard drive has failed SMART status
14. Mac external hard drive is ejecting itself
15. Mac hard drive’s encryption password is lost

1. Mac hard drive is running slow

Problem: Aging and prolonged usage can slow down a Mac startup disk. Also, a lot of other factors can degrade your Mac performance, like hard drive becoming full, macOS being outdated, several log-in items enabled, many apps running in the background, hardware issues, etc.

Solution: There are several things you can do to give your Mac a performance boost:

  • Delete large unwanted files, unused apps, and duplicate data from the hard drive
  • Clean up the Desktop and log in items
  • Update your macOS and third-party applications
  • See a list of background processes in Activity Monitor and quit the ones you don’t need
  • Upgrade your Mac hardware and firmware
  • Repair your startup disk with Disk Utility
  • Remove inessential plugins, widgets, and Internet caches from Safari

The above list of activities often looks simple, but it isn’t. Taking out the time and patience to manually clean up Mac hard drive and perform other tune-up tasks can get frustrating.

2. Mac hard drive space is disappearing

Problem: Low free space is a concern for Mac users if they are using a low capacity storage drive (say 128 GB SSD). “Your startup disk is almost full” is a standard error seen by such users. Even if you keep your essential data in iCloud and large multimedia files in an external storage drive, your Mac storage drive free space will disappear automatically. The low storage happens due to the buildup of junk files, temporary files, caches, logs, and leftovers of application.

Solution: To resolve the drive space disappearing issue, you need to make more space available on your startup disk by deleting temporary files:

To remove caches:

  1. Open Finder from Dock.
  2. From the Menu Bar, click on Go, then click Home.
  3. Click the cog icon from the top pane and select “Show View Options.”
  4. On the pop-up window, select the “Show Library Folder” checkbox, then close it.
  5. Go to Library > Caches.
  6. Delete all the caches.

Alternatively, you can do the following:

  1. Open Finder from Dock.
  2. From the Menu Bar, click on Go, then click “Go to Folder.”
  3. From the dialog window, type ~/Library/Caches, then click Go.
  4. Delete all the caches.

You can delete all the temporary files from specific folders present in the Library folder, such as Logs, unneeded iTunes files, and Application Support files. This frequent temporary file removal will increase free space on your Mac and prevent the drive disappearing issue.

Read More: How to Free Clean Up Your Mac Startup Disk?

3. Mac hard drive is not showing up in Disk Utility

Problem: The Mac storage drive fails to show up in the Disk Utility window.

Solution: Mac hard drive not appearing in the Disk Utility window is one of the worst problems that a storage device could face. In most cases, the storage device is dead either entirely or partially. In case of an unmounted Mac hard drive, the drive still appears in the Disk Utility, but in a greyed-out (disabled) form.


Fortunately, a Mac hard drive recovery software rescues files stored on the unmounted media, which can be erased later for reuse.

In the case of a dead Mac hard drive, you can replace the device after recovering lost data with the help of a trustworthy data recovery service provider.

4. Disk Utility can’t repair Mac hard drive

Problem: By using the First Aid tab in Disk Utility, you can fix your hard disk drive or other storage drives for errors, bad sectors, etc. But this is not always the case. Sometimes, you’ll encounter the message “Disk Utility can’t repair this disk.” This error occurs when Disk Utility fails to repair your storage drive.

Solution: Use the “file system consistency check” (fsck) command in Single User Mode to review and repair the basic structure of your storage drive. But, first, back up the drive to another external storage medium to ensure you don’t lose data while troubleshooting the error. Next, perform the following steps:

  1. Start or restart your Mac, then immediately press-hold Command + S keys until white text appears on the startup screen. Your Mac will boot into Single User Mode.
  2. On the command prompt, type “fsck –fy” and hit Return. Don’t interrupt till the command finishes, as this can result in data loss.
  3. When you see the message “The volume was modified” or “The volume Macintosh HD could not be repaired,” use the above command again.
  4. Use the command multiple times until you get the message “The volume Macintosh HD appears to be OK.” Type exit to restart your Mac.

Related Blog: Best Ways to Free Repair Failed Mac Hard Drive

5. Mac external hard drive is not mounting or is unrecognized

Problem: When you connect an external hard drive to Mac, it mounts and shows up on the Desktop. It also appears in Finder. However, sometimes, the disk can fail to mount when you connect it. In such a case, it won’t appear even in Finder.

Solution: Some common fixes you can try are:

  • Set your Mac to show all mounted drives on the Desktop.
  • Unplug and re-plug the drive.
  • Try to connect it with a different cable.
  • Use a different USB port to connect it.
  • Try connecting it to another Mac.

If none of the above solutions works, there might be something wrong with your external hard drive. Try to back up your hard drive via Disk Utility or a third-party cloning utility, so that later you can erase and reformat the drive with a new file system. However, if there is no backup of your data and you are unable to clone the troubled hard drive, then opt for a Mac data recovery software to recover data from the unmounting Mac hard drive.

Read Case Study: A whopping 94% of data recovered from an unmounted external hard drive on MacBook Pro.

6. Mac hard drive data is lost permanently

Problem: Sometimes, data loss from a Mac hard drive is inevitable. There could be any reason for data loss such as accidental deletion, emptying Trash, hard drive erasure, physical damage or technical failure, virus/malware attack, system crash, etc.

Solution: Employ the methods presented next to restore or recover your permanently lost data.

Restore from Time Machine: When you’ve backed up your Macintosh HD to an external Time Machine backup drive, you can restore your lost, deleted, or corrupt files from Time Machine. Go to Menu Bar, click Time Machine, and then click Enter Time Machine. Search your lost files or folder by using the Timeline or Up/Down arrow. Select all the required items and click Restore. Your files and folders will restore to their original location.

Recover by using software: If Time Machine is of no help, you can employ a data recovery software for Mac to recover your lost data. But you must stop using the drive immediately to prevent any overwriting. Next, download the trial version of Stellar Data Recovery Professional for Mac on your system. Scan the hard drive for recoverable data then preview the scanned items. When satisfied with the recovery result, activate the software to recover all your missing data to a different drive location.

7. Mac hard drive’s partition is deleted

Problem: While trying to resize or reformat a partition, many users report accidentally deleting their APFS partitions containing essential data. Also, due to issues such as partition table damage, technical trouble with the drive, bad sectors, or virus attacks, one or more hard drive partitions can get accidentally deleted.

Solution: Restore the lost or deleted partition with the help of Time Machine backup. However, in the absence of backup, use Stellar Data Recovery Professional for Mac software to find the deleted partition(s). This application helps locate deleted partitions on any APFS, HFS, HFS+, FAT, NTFS, or ex-FAT based storage drive. It can quickly revive deleted volumes on your iMac, Mac Pro, MacBook Pro, MacBook Air, or Mac mini. Also, if the volume(s) on your Mac fails to mount, then this software helps recover the partition data quickly.

8. Mac hard drive is not booting

Problem: Sometimes, your Mac hard drive won’t boot. This issue could happen due to file system corruption, bad sectors, electronic component damage, or other hard drive issues. As a result, all your valuable photos, videos, documents, etc. that are stored on your Mac hard drive turn inaccessible.

Solution: Implement the following methods to get back your data from a non-booting Mac.

Access your non-booting Mac by using Target Disk: Connect your non-booting Mac to a working Mac by using FireWire or Thunderbolt cable. Power on your working Mac. Next, turn on your non-booting Mac, then immediately press and hold the T key. Release the key when FireWire or Thunderbolt icon appears. Now, you can access your non-booting Mac hard drive from your working Mac.

Use Time Machine Backup: If you have Time Machine backup, connect it to your non-booting Mac. Next, power on the Mac and press-hold Command + R keys. Release them when Apple logo appears. Your Mac enters macOS Recovery mode. From the macOS Utilities window, click Restore from Time Machine Backup, then click Continue. Perform the on-screen instructions to erase your Mac hard drive, reinstall macOS, and restore data from the Time Machine backup drive.

Boot your non-booting Mac by using recovery drive: Download and install Stellar Data Recovery Professional for Mac on another working MacBook, iMac, or Mac mini. Next, create a recovery drive by using a thumb drive of at least 8 GB. Connect the boot drive to the non-booting Mac. Power on your Mac, then press-hold the Option key. Release it when the Startup Manager opens. Next, choose the Recovery Drive. In the macOS Utilities window, select Stellar Data Recovery, then click Continue. Use the on-screen instructions to recover data from the non-booting Mac.

Read More: How to recover data from a non-booting Mac

9. Mac hard drive is making a clicking noise

Problem: Mac hard drives typically contain platters on which a magnetic arm reads/writes data. The platters can get damaged by a drop or jerk. If you hear a clicking noise coming from your Mac hard drive when you boot your Mac, this could mean your hard drive has suffered physical damage.

Solution: In such a scenario, there isn’t much you can do except:

  • Back up all your essential data
  • Run the Apple Hardware Test
  • If you can’t back up, use Mac disk cloning software to clone the drive

You probably need to replace your hard drive with a new one or at least get it checked by experts. DO NOT attempt to open it yourself as that could further the damage and lead to permanent data loss.

10. Mac hard drive is not detected in Windows

Problem: When you connect a Mac-based storage drive on a Windows PC, it won’t appear on File Explorer. This issue arises due to the incompatibility of file systems. You may have formatted your storage drive in the APFS or HFS+ file system, which is compatible exclusively with macOS. No other operating system is harmonious with the proprietary file system format of Apple.

Solution: To fix the issue, do the following:

  1. Back up all the data from the storage drive from its compatible operating system.
  2. Format the drive in the ex-FAT file system. (You can even format your USB flash drive in FAT32, but it will only allow storing of files with a size limit of 4 GB.)
  3. Restore the backed up data to the storage drive.

Now, you can use the storage drive in both Mac as well as Windows computers. Windows can read-write on ex-FAT as well as FAT32 file system formatted storage drive.

Related Blog: How to Recover Data from Mac Hard Drive on Windows

11. Unable to partition Mac hard drive

Problem: Partitioning a hard drive is a reasonably simple task by using Disk Utility. But sometimes, Disk Utility fails to create partitions on a hard drive or perform other partitioning-related operations.

Solution: If you are good at the command-line interface, use diskpart command in Terminal to partition your Mac hard drive. Check its manual for parameter and steps. Or else, employ a disk partitioning software to create, delete, format, resize, hide or reveal partitions.

Read More: How to partition macOS Mojave startup disk?

12. Bad sectors in Mac hard drive

Problem: Detecting bad sectors on your hard drive isn’t easy. You might suspect that your Mac hard drive has started developing bad sectors if some information suddenly goes missing or the drive throws error accessing a file. For example, you saved a file, but on trying to access it later, the OS throws out an I/O error that due to a bad-block it can no longer read.

Solution: There are several fixes to this problem:

  • Check the SMART status of your hard drive by using Disk Utility.
  • Boot into macOS Recovery mode, then go to Disk Utility > First Aid. Click Run to repair the hard drive. Keep running First Aid until it says there are no errors.
  • If the repair doesn’t work, back up the Mac storage drive, then erase it. And then, finally restore the backup.

13. Mac hard drive has failed SMART status

Problem: Mac hard drive uses SMART (aka Self-Monitoring, Analysis, and Reporting Technology) to monitor internal disks and to check for issues. If the SMART status on your Mac hard drive reports error or failure, it usually means the hard drive is about to fail permanently.

Solution: You can still recover data from a failed hard drive. To check all recovery possibilities, follow these steps:

  • For an external hard drive, open Disk Utility, then select the failing hard drive from the left pane. Click First Aid, and then click Run to initiate the repair process.
  • For startup disk (Macintosh HD), start or restart your Mac, and immediately press-hold Command + R keys. Release the keys when the Apple logo appears. On the macOS Utilities window, select Disk Utility, then click Continue. Select the startup disk from the left pane and then click First Aid. Click Run to repair the startup disk.
  • If the repair process doesn’t work, back up all the files present on the disk and then erase it.
  • Once the erasure completes, check the disk’s SMART status, which should ideally show the hard drive as “Verified”.

If none of the above solutions work, you may need to repair your hard drive or replace it with a new one.

Read More: Premium Storage Drive Monitoring Software for Mac

14. Mac external hard drive is ejecting itself

Problem: Some of you may have tried replacing your Mac CD/DVD drive with a large capacity hard drive. By doing this, you’ve augmented your Mac’s storage capacity. But you may have also noticed auto hard drive ejection issue after a few minutes of drive idleness.

Solution: To resolve the eject issue, you need to tweak the power management settings of your Mac, as shown here:

  1. Go to Finder > Applications > Utilities > Terminal.
  2. On Terminal, type “pmset –g | grep disksleep” and hit Return.
  3. Check the value of disksleep. If it is low, you need to provide a significant number.
  4. Type “sudo pmset –a disksleep #” (here replace # with a suitable number) and hit Return.
  5. Provide the admin password when prompted.
  6. Check the changed sleep value by using “pmset –g | grep disksleep” command.

The above solution will fix the drive auto-eject problem. Now, you can use the hard drive to save and access data as usual.

Related Blog: Recover Lost Data after Ejecting Mac USB Hard Drive Cable Abruptly

15. Mac hard drive’s encryption password is lost

Problem: Many of you use Apple File Vault to encrypt data on your Mac hard drive. File Vault uses XTS-AES-128 encryption with a 256-bit key to help prevent unauthorized access to the data on the startup disk. But every encryption works in conjunction with a decryption key that decrypts the information before it can be accessed. Mostly, this decryption key is a password chosen by you. If you lose or forget your decryption password, you lose access to your data permanently.

Solution: Make sure you are typing the password correctly. Turn off the Caps Lock and choose the Show Password option just to be doubly sure. If you’re still locked out, try one of these:

  • If the password field shows a question mark, click it to display a password hint. The hint might help you to remember the forgotten password.
  • Try to log in with the Apple ID password that you use for iCloud.
  • Use your Apple ID to reset your password, which then resets your keychain.
  • Have an administrator reset the login password.
  • Use the recovery key that you noted down when you turned on File Vault disk encryption (for this File Vault must be on).
  • Reset password using the Reset Password assistant (for this File Vault must be on).

If none of the above steps works, contact Apple Support for help!

Related Blog: How to Encrypt, Decrypt, and Recover Deleted Mac Files


In this post, we outlined the worst problems you may face with your Mac hard drive, SSD, or other storage drives and partitions. But by implementing the solutions shared in the post, you can avoid data loss. Remember to perform critical troubleshooting steps only after taking a full backup of the storage medium.

In case you lose valuable data during or after performing the troubleshooting steps, leverage Stellar Data Recovery Professional for Mac to get back your data. The software is user-friendly and recovers lost data in 3 key steps: Select, Scan, and Recover.

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