If you have an external drive that suddenly won’t mount on your Mac, this could happen for a number of reasons. It’s possible that the disk is malfunctioning, or that your computer isn’t recognizing it properly. Sometimes a simple reboot of your machine is enough to fix the issue. When an external hard drive won’t mount on a Mac, there are several approaches you can take to the problem.
Common Situations Where Your External Hard Drive Might Not Mount on a Mac
There are different situations that may cause your drive to not mount properly on a Mac. Here is an outline of problems and possible solutions.
| Problem | Solution |
| Drive doesn’t appear | Fix 1: Change macOS Drive Display Settings Fix 2: Remount External Disk in Disk Utility Fix 3: Reconnect Your Drive Fix 4: Restart Your Mac Fix 5: Use Disk Utility’s First Aid Tool Fix 6: Reset your NVRAM, PRAM, SMC Fix 7: Reformat Your Drive |
| Drive is not formatted correctly | Fix 7: Reformat Your Drive |
| Drive is corrupted | Fix 5: Use Disk Utility’s First Aid Tool Fix 7: Reformat Your Drive |
How to Fix Your External Hard Drive Not Showing Up on a Mac
In order to fix a hard drive that won’t mount on a Mac, you should try the following steps. Not all of them will work, and sometimes you might not reach a solution in the end. Make sure to take a structured approach to this and note your results.
Fix #1: Change macOS Drive Display Settings
It’s possible that your disk drive is simply prevented from showing up in your system settings. To check if that’s the case – and fix it – follow these steps:
- Start Finder
- Go to Finder -> Preferences
- Click General
- Make sure Hard disks is checked
Fix #2: Remount External Disk in Disk Utility
One of the simplest fixes when a disk won’t mount on a Mac is to try remounting it through Disk Utility. To do this, follow these steps:
- Start Disk Utility
- Select the disk drive if you see it in the list
- Click Mount
Fix #3: Reconnect Your Drive
This one is straightforward. Simply unplug the drive and plug it back in. If an HDD won’t mount, sometimes all it needs is a restart of the connection to get it running again.
Fix #4: Restart Your Mac
Another simple fix that works surprisingly often is to just restart your computer. Sometimes things can get stuck behind the scenes in non-obvious ways, and the only way to fix the problem is to give your Mac a reboot.
Fix #5: Use Disk Utility’s First Aid Tool
Using Disk Utility is another option for fixing a drive that won’t show up. The first step varies depending on your processor type, but it’s the same regardless if you have Mac Big Sur, Mac Monterey, Mac Catalina, or any other distribution.
- Restart your Mac
- Using an Apple processor: Keep the power button held until you see the startup options window. Click on Options, and then on Continue.
- Using an Intel processor: hold down Command + R until you see the utilities window
- Select Disk Utility and click Continue
- Click on View -> Show All Devices
- Select your hard drive from the list on the left
- Click First Aid
- Click Run
Fix #6: Reset your NVRAM, PRAM, SMC
Resetting your NVRAM, PRAM, and/or SMC can occasionally be useful when dealing with tricky issues that you can’t link to anything else.
- Shut down the computer
- Press the power button and keep it held down for 10 seconds
- Check if the problem persists. If it does, shut down the computer again
- Hold down the right shift, left option, and left control keys for 7 seconds, and then press and hold the power button for 7 seconds
Fix #7: Reformat Your Drive
In more extreme cases, such as a corrupted filesystem on the drive, you might need to reformat the drive entirely. Note: this will erase all data on the hard drive!
- Start Disk Utility
- Select the disk drive if you see it in the list
- Click Erase
Your drive will now be erased and automatically formatted. If you need to recover your files afterwards, this can be done with a tool like Disk Drill, provided you use a separate drive for recovery.
How to Recover Data from an External Disk That Isn’t Mounting on a Mac
If your disk drive isn’t mounting at all, even with the above steps, you might still be able to recover some – or all – of the data on it. To do this, you generally have two options available: use data recovery software like Disk Drill, or send your drive to a data recovery center.
Data Recovery Software
You can use a tool like Disk Drill to recover data from your external hard drive on a Mac. This works with a Seagate external hard drive or any other model on the market. It also doesn’t require the use of the Mac Terminal, making it a beginner-friendly option. As long as your drive is showing up in Disk Utility, this approach should work.
- Download and install Disk Drill
Data recovery for free
Your Companion for Deleted Files Recovery(Video) How To Fix External Hard Drive Not Mounting On Mac - Start Disk Drill
- Select your drive
- Select All Recovery Methods
- Click Search for lost data and wait for the scan to finish.
- Go through the discovered results, select the files you want to recover, and click Recover
- Make sure to recover them on a separate hard drive! Using the same drive may corrupt your data further!
Data Recovery Service
Data recovery services are professional organizations that specialize in extracting data from dead or damaged drives. They typically have access to controlled laboratory environments where the disks can be safely disassembled and accessed externally.
Using this type of service can be expensive and time-consuming. There’s also no guarantee that they will be able to recover your data. However, if your data is really valuable and you’ve already exhausted all of the above options, this may be your only chance.
Cleverfiles Data Recovery Center is one of the most popular companies on this market. You should get in touch with them as a starting point if you’re not sure where to even begin your search.
How to Protect Your External Drive on a Mac
You must always be careful with an external drive on your Mac. If you’re already at the point where you’re asking “How do I force my Mac to mount an external hard drive?”, it’s obviously too late for that. But you can still keep the following points in mind for future reference to avoid problems down the road.
- 💾 Always backup your data on a regular basis. Ideally, keep at least two physically separate copies of the data if it’s really important to you.
- ☁️ Use a cloud service to regularly store photos and other similar data.
- 🛑 Don’t download suspicious apps, especially from non-approved sources – those could contain malware.
- 💽 Keep the drive physically safe. Hard drives are sensitive to physical damage and can easily be disabled by knocking them around too much.
- 📀 Always eject your drive from the operating system before physically unplugging it.
Conclusion
Knowing how to force an external hard drive to mount on your Mac can be useful if you run into a situation where it’s not getting recognized by the operating system. There are various approaches you can take here, and it’s a good idea to study them in detail before you actually need them, so that you’ll be better prepared if the worst happens one day.
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FAQ
This can be caused by a number of factors. It’s possible that the drive is damaged, its filesystem could be corrupted, or you may have an error in your operating system itself.
To fix a drive that won’t mount on a Mac, try these fixes:
- Remount the disk in Disk Utility
- Restart your Mac
- Reformat your drive
- Change your macOS drive display settings
- Reconnect your drive
- Use Disk Utility’s First Aid tool
This means that the drive is physically connected to your Mac, but it’s not set up for access by the operating system.
To mount an unmounted disk on a Mac, follow these steps:
- Start Disk Utility
- Select the disk drive if you see it in the list
- Click Mount
Stefan Ionescu
A technology passionate, Stefan holds an MSc in geological engineering and currently serves clients as a freelance writer. Despite having a master's in geological engineering, Stefan's passion for writing and technology t...
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A technology passionate, Stefan holds an MSc in geological engineering and currently serves clients as a freelance writer. Despite having a master's in geological engineering, Stefan's passion for writing and technology t...
Read full bio
Approved by
Brett Johnson
This article has been approved by Brett Johnson, Data Recovery Engineer at ACE Data Recovery. Brett has a Bachelor's Degree in Computer Systems and Network, 12 years of experience.
This article has been approved by Brett Johnson, Data Recovery Engineer at ACE Data Recovery. Brett has a Bachelor's Degree in Computer Systems and Network, 12 years of experience.
FAQs
How do I force my Mac to mount an external hard drive? ›
- Go to Finder > select Applications folder > find and open Utilities > click Disk Utility.
- Choose the external volume from sidebar > select “Mount” tab at the top center.
Why is my external hard drive not readable on Mac? The most common issue is your drive being formatted incorrectly. In this case, you'll need to change the format of your drive using Disk Utility. Other reasons might include issues with power supply, faulty cable, and your drive being corrupted or broken.
How do I fix my external hard drive not showing full capacity? ›- Update Hard drive driver.
- Format Hard drive via command prompt.
- Backup data and initialize the Hard drive with disk management.
- Check for bad physical sectors or replace the disk.
If you eject a volume, you can use Disk Utility to mount the volume so that it's available in the Finder. In the Disk Utility app on your Mac, select the volume you want to mount. Click the Mount button .
Why is my external ExFAT drive not mounting Mac? ›Corruption issues: In some cases, the ExFAT USB might not mount on the Mac operating system due to corruption. That prevents mounting. You will need to rebuild the directory or run the repair on the USB. Missing driver software: Another reason could be the lack of essential driver software for reading the ExFAT USB.
How do I force my Mac to recognize a USB? ›Open System Information and disconnect the USB device from your computer. Wait a few minutes, and click File > Refresh Information. Reconnect the USB device. You should see a device disappear from System Information when you remove the USB device, and it should appear again when you reconnect it.
How do I get my hard drive to show up on my Mac? ›In the Finder on your Mac, choose Finder > Settings. Click General, then select the items you want to see on the desktop. For example, if you select “Hard disks,” icons for your hard disks appear on your desktop. Click Sidebar, then select the items you want to see in the Finder sidebar.
How do I fix my Seagate external drive not showing up Mac? ›Open Finder > Applications > Utilities > Disk Utility
If the drive is not detected in Disk Utility then see the System Information/System Profiler section. If you are using macOS 10.13 or higher then click view in the upper left and select “Show All Devices” which allows you to see both the disk as well as volumes.
The Seagate external hard drive beeping and not recognized on Mac could be resulted from a damaged cable or the cable not supplying enough power. Try using another cable, an external power source, or a self-powered USB hub to connect your Seagate drive with Mac. Also, try different ports on the Mac.
Why is my drive showing less space than actual? ›Your drive shows up smaller than advertised because storage drive capacity is calculated and reported slightly differently than other capacities in computing. If you look at the specifications of any storage device, you will see a note that says something along the lines of ”1 GB = 1 billion bytes.
Why is my hard drive only showing partial capacity Mac? ›
Reasons Why the Hard Drive Only Shows Partial/Half Capacity
Many reasons can cause a hard drive with an incorrect capacity issue: Virus or malware attack. Out-of-date hard drive driver. Improper formatting.
If your internal hard drive is not showing up, it might be because it is not initialized or it needs formatting. Ensure your disk is properly connected to the motherboard with the SATA cable. Due to some BIOS settings, your HDD might also not be visible in Windows 10.
How do I convert exFAT to FAT32 on Mac? ›- Insert your memory card into your computer.
- Open Disk Utility.
- Choose your memory card and click Erase to access the disk-formatting settings.
- Choose MS-DOS (FAT) from the format drop-down list.
- Click Erase to format.
Launch Disk Utility (from Applications > Utilities > Disk Utility). Select the drive in the left-hand sidebar. Click Erase. From the Format menu, select ExFAT.
How do I change from FAT32 to exFAT on Mac? ›Convert "FAT32" to "exFAT" on Mac
Step 1: Go to "Applications"->" Utilities" and launch "Disk Utility". Step 2: In the Disk Utility interface, select the external drive that you want to format. Step 3: Under the "Erase" tab, select the "exFAT" file type from the menu list.
- Open Device Manager and then disconnect the USB device from your computer. Wait a few moments and then reconnect the device. ...
- Connect the USB device to another USB port.
- Connect the USB device to another computer.
- Update the USB device drivers.
What format should a USB be for Mac? APFS is the original default file format used on macOS, so it's your best bet for formatting a USB. However, you should note that APFS is not compatible with some older versions of macOS — for those you might need to use Mac OS X Extended or other formats.
How do I reset my USB port on my Mac? ›Shut down the computer if you don't see one of your USB devices in the device list. Turn the computer back on. Hold the "Command-Option-P-R" keys together before the gray screen appears until you hear the startup sound for the second time. Release the keys.
What does not mounted mean on Mac? ›When the Macintosh HD is not mounted/Showing up in Disk Utility, it means that the drive is not available for the operating system. macOS can't find a mount point to read and write the Macintosh HD. Then, your Mac won't turn on.
How do I reset my Seagate External hard drive Mac? ›- Make sure the storage device is connected to and mounted on the computer.
- Select Go > Utilities in the Finder menu bar.
- In the Utilities folder, double-click Disk Utility. ...
- Select the Seagate drive in the left column.
- Click the Erase tab.
- Choose a format from the drop-down window.
- Enter a name for the volume.
Why I Cannot add files to my Seagate External hard drive Mac? ›
This usually happens because the drive is formatted with Microsoft's NTFS file format. On macOS, you can only read disks in this format, not write to them. As a consequence, you won't be able to add, change, or delete files. You can use a third-party app to write to an NTFS disk on a Mac.
How do I fix an undetected Seagate external hard drive? ›Quite often, issues such as a Seagate external hard disk light blinking but not being detected can be fixed by simply rebooting the computer. To do this, disconnect your external hard drive from the computer. Now turn off the PC for at least 1 minute. Then reconnect the external hard drive and turn on the computer.
Is Seagate external hard drive compatible with Mac? ›Seagate, Maxtor, and Samsung-brand external hard drives do not require additional drivers to function with modern Windows (Vista+) or Mac OS X (10.4+) operating systems. These external drives are supported by the standard device drivers that are already included in these operating systems out of the box.
How do I fix a disk space problem? ›Free up space with Disk Cleanup
In the search box on the taskbar, type disk cleanup, then select it from the results. Select the drive you want to clean up files for, then select OK. Select the check box next to the type of files you want to delete. (To view a description of each type of file, select the name.)
1 TB equals 1,000 gigabytes (GB) or 1,000,000 megabytes (MB). Now, let's compare that to physical storage devices we use every day. Compared to the average smartphone, 1 TB of storage is the same as roughly 16 (64 GB) iPhones or Samsung Galaxy devices.
Why is my 1TB hard drive only showing 100MB? ›Generally 100MB means a Partition on which Bootloader is written. You might have installed some OS and put the boot loader on this 1TB drive. Rest of the TBs would be as Unformatted Partition. If you are sure there is nothing on this Drive yet.
How do I restore my hard drive to full capacity? ›- Fix 1: Perform a Quick Format of the Hard Disk.
- Fix 2: Delete the Partition and Reformat it via Disk Management.
- Fix 3: Use the Diskpart Utility to Format the Drive.
- Fix 4: Update the Relevant Hard Disk's Drivers.
- Fix 5: Manually Install the Software for the USB Driver.
This is completely normal. Odd but normal. Unfortunately. A hard drive described as being a terrabyte is actually 1,000,000,000,000 bytes, the operating system reads in 1024KB blocks so you end up with it reporting only 931GB and you "lose" 69GB in the conversion.
Why does my 4TB hard drive only shows 2TB Mac? ›They are different slightly in supported partition amounts, disk capacity, OS compatibility and boot mode. For example, GPT can support disk larger than 2TB but MBR partition style cannot. And this is the cause of 4TB SSD or 4TB HDD only showing 2TB.
How do I reformat my external hard drive? ›Plug in the drive and open Windows Explorer. Right-click the drive and choose Format from the drop-down menu. Select the file system you want, give your drive a name under “Volume label,” and make sure the Quick Format box is checked. Click Start, and the computer will reformat your drive.
Why is my 1TB drive only 32gb? ›
Operating System: Windows have a 32 GB format limitation for FAT 32. That means if you formatted the drive in FAT 32 with Windows, the largest partition supported is 32 GB. You will need to format the drive in NTFS if you want to partition the drive larger than 32 GB.
Why is my 4tb hard drive not showing full capacity? ›The possible reasons for 4TBdrive not showing full capacity: The hard drive has been initialized to a wrong partition table - MBR, which only supports a disk less than 2TB. The hard drive driver or firmware is out of date. Bad sectors make the hard disk drive unable to read correctly and show the wrong capacity.
Why does my 3TB drive only show 746GB? ›3TB external suddenly becomes 746GB unallocated is commonly caused by incorrectly configured system settings or irregular entries in the Windows registry. If you are received this error, it means your system operation may have a malfunction.
Why is my 3TB showing as 746GB? ›In a word, if a new 3TB hard drive only shows 746GB, you may convert it to GPT disk, or upgrade your Intel® Rapid Storage Technology (RST). Besides, if it's an external disk, you had better connect it to the computer via SATA.
How do I restore my USB back to full capacity? ›- Select the USB drive to format. Connect the USB drive or pen drive to your computer. ...
- Set the drive letter and file system on USB. ...
- Check "Yes" to confirm formatting USB. ...
- Apply the changes.
If you are basically married to your gaming PC, you might even want to upgrade to 32GB. It is often considered overkill to invest in a 32GB storage unit, but there are a few benefits. First, you can pretty much-run anything with no sweat. Your computer has enough room at the proverbial table to perform well.
Is exFAT better than NTFS? ›In a debate regarding exFAT vs NTFS vs FAT32, NTFS is the best format for storage devices with Windows operating system. However, exFAT is best for portable storage devices due to more efficient power and memory management. It also allows you to use a storage device on both Windows and macOS.
Why is my 4TB drive only 3.63 TB? ›The reason the drive doesn't show as 4TB in your OS is because, since the beginning of time, hard drive manufactures consider 1 kilobyte as 1,000 bytes, 1 megabyte as 1,000 kilobytes, 1 gigabyte as 1,000 megabytes and 1 terabyte are 1,000 gigabytes.
Why is my Seagate 3TB hard drive not showing full capacity? ›If the 3TB drive not showing full capacity problem does not result from the wrong partition table, it could be the problem of a computer virus or hidden recovery partition. As for hidden recovery partition, you can use the feature Change Drive Letter and Paths in Disk Management to make it visible.
What is 3TB unlock? ›GIGABYTE 3TB+ Unlock optimizes HDD storage space by allowing the user to create a virtual drive with space that exceeds 2048GB, the maximum amount of storage recognized by 32bit versions of operating systems such as Windows XP.
How do I format a 3TB hard drive? ›
- Right-click on the Windows button, select "Disk Management".
- Right-click the 3TB hard drive shows the wrong capacity. Choose "Delete Volume...".
- When the hard drive shows as unallocated space, right-click the disk and choose "Convert to GPT Disk".
However, a Full Format can take up to 3 hours. If this hard drive stores a chunk of data, it could take you a half day.
What is Windows disk management? ›Disk Management is a system utility in Windows that enables you to perform advanced storage tasks. Here are some of the things Disk Management is good for: To setup a new drive, see Initializing a new drive. To extend a volume into space that's not already part of a volume on the same drive, see Extend a basic volume.
Why Windows was unable to complete the format? ›What causes the “Windows was unable to complete the format” error? There can be multiple different causes for this error. Most of the time, it is either related to poor system configuration, or an issue with your drive. In rare cases, even malware can cause this error, especially if it's on the drive itself.
Why is Windows unable to format SD card? ›A write-protected SD card is set to a read-only capacity and can't be formatted. Hence, you will be unable to format sd card. Write protection could lead to the "Windows can't format SD card" issue. If so, all you need is to eliminate your card's write protection to make it work without a glitch.