Data Recovery

How to Recover Mac Partitions That Have Been Deleted or Lost (2021)

Few errors feel like more of a punch in the gut than one arising from a deleted or corrupted partition. Sure, losing a single important file stings. But an entire partition? That can be downright traumatizing.

But thankfully, if you do find yourself in that sorry situation, all hope is not lost. There are actually a few ways to recover a deleted partition on a Mac and bring your lost files bustling back to life.

This guide outlines three techniques for recovering your lost data thanks to a corrupted, deleted, or lost partition on a Mac.

macOS Partitions Explained

Partitions are logically separated storage systems within an individual disk. Think of partitioning like splitting up your current hard drive (or an external drive) into two independent containers. Effectively, you’re creating two different drives you can run and organize as you wish.

There are a few benefits to partitioning your hard drives. You can:

  • Run multiple operating systems (e.g., macOS and Windows) on the same hardware.
  • Test a new OS without compromising your current one.
  • Simplify your backups by isolating key files from OS files and applications.

The “why” behind partitioning is usually to achieve a set goal rather than doing so on a whim. That’s because there are real disadvantages to partitioning drives. Namely, it reduces the storage space of the partitions as the drive is split.

💡 If your Mac uses APFS (more on that in a bit), you can create a volume instead of a partition to combat that space problem. While a partition’s storage is set in stone, a volume’s is flexible. As such, volumes can expand or shrink between themselves to accommodate your needs. It’s partly why Apple recommends creating volumes rather than partitions.

Disk Utility makes it incredibly easy to create partitions and volumes on your Mac.

*We’re using macOS Big Sur Version 11.6. The process may vary a bit for other versions.

To add partitions or volumes to your Mac:

  1. Head to Disk Utility by locating it in Finder > Applications > Utilities (or save yourself some time and search Spotlight via the menu bar or Command + Space).Window showing where to find Disk Utility for partition recovery on macOS
  2. Select the disk and volume you’d like to partition and click Partition.Window in Disk Utility showing where the partition button is
  3. Click the + sign to add a partition or volume. You can then drag the slider in the pie chart to set your size. You can also type in the storage space in the field to the right. Then select the format, name your partition or volume, and click Apply. Simple as that.
    Window showing the partition screen in disk utility for Mac partition recovery

Types of File System Formats

Partitions are organized according to their file system format. On Macs, there are three supported file system formats for an up-to-date macOS (Big Sur 11.0).

  • Apple File System (APFS) – This file system from Apple is the default system for computers using macOS 10.13 or later. It’s optimized for Flash and SSD storage but can also be used with older systems featuring hard disc drives and external, direct-attached storage.
  • Mac OS Extended (HFS+) – The previous Apple standard since 1998, this file system is used by computers with macOS 10.12 or earlier. HFS+ is a journaling file system that keeps track of changes to aid in recovery after a system crash.
  • MS-DOS (FAT) & exFAT – Microsoft created these two formats. The macOS supports them for compatibility with Windows-formatted external storage devices or dual operating systems.

To learn more about these file systems, check out the guide from Apple.

Mac Partition Recovery: 3 Proven Methods for Deleted or Lost Partitions

A partition can be lost, deleted, or corrupted for a variety of reasons. An unexpected shutdown, improper disk ejection, hardware malfunction, viruses—all can result in an infuriating loss of important data.

But don’t worry. There is still some hope yet, even if your partition is nowhere to be found.

Below are three different methods of partition recovery on macOS so you can get back to business as usual.

Case #1: Recover Specific Deleted Files from a Mac Partition

If you’re just looking to bring back a few essential files from your damaged or lost partition, you may be in luck. Apple doesn’t offer a solution of its own, unfortunately. But several third-party apps can help here.

One of the best ones out there today is Disk Drill. Disk Drill is especially user-friendly, has an intuitive interface, supports several file systems, devices, and file formats, and boasts an impressive 90% recovery rate. It’s why Disk Drill has become a go-to option for Mac partition recovery with users of all experience levels.

Plus, it offers both free and premium options as well as a suite of additional features like disk monitoring, data protection, duplicate file remover, and more.

To learn more about the features and use cases for this data recovery software, have a look at our official Disk Drill review.

Here’s how to recover your specific deleted files from a Mac partition using Disk Drill.

To recover your deleted files from a Mac:

  1. Download Disk Drill and install it on your Mac. If possible, install it on a partition other than the damaged partition in question.Download and install Disk Drill for Mac partition recovery
  2. Install it by dragging the icon over to the Applications folder.Install Disk Drill in your Applications for Mac partition recovery
  3. Launch Disk Drill and give it the necessary permissions to recover your files using the instructions from the popup window.Launch Disk Drill and grant permissions for Mac partition recovery
  4. Select the drive and partition you’d like to recover files from. Make sure your targeted device is connected to your computer.Select your drive on Disk Drill for Mac partition recoveryYou can also click Info to view info about the partition and parent hard disk.
    View detailed info about the partition and drive in Disk Drill for Mac partition recovery
  5. Find and select the files you’d like to recover from the list and hit recover.
    Find your files and recover for Mac partition recoveryMake sure each selected file allows for a proper preview (click the “eye” icon next to the file name). Only files that can be previewed are fully recoverable.
    Test each file for an accurate preview for Mac partition recovery
  6. Choose the location you’d like to restore the files to, hit OK, and you’re done! Your files will then be restored to your selected location.

Case #2: Recover a Lost Partition on a Mac

While Disk Drill’s data recovery software is rich in features and functionality, it cannot fully recover a lost partition on a Mac. However, that doesn’t mean you are out of options.

If you find yourself needing to recover an entire partition, you can use the free tool TestDisk. TestDisk is open-source software that fixes partition tables, recovers entire deleted partitions, and makes non-booting disks bootable again. It’s also completely free to use and installable using Homebrew.

All that said, it isn’t exactly user-friendly since it doesn’t have a graphical interface. As such, it needs to be run through macOS’s Terminal. But don’t let that scare you off. It’s quite easy to use, provided you have the proper roadmap.

Follow the steps below to use TestDisk to recover lost or deleted partitions on your Mac.

To recover full partitions using TestDisk:

  1. Install TestDisk by first opening up Terminal. You can do that by pressing Command + Space, typing Terminal, and pressing Enter.Spotlight search for terminal for partition recovery on macOS
  2. Input the following command to install Homebrew:
    ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)" 2> /dev/null

    You may be prompted to enter your Mac user password (shown below). Type in your password like normal and hit Enter. The window will not show your password characters filling in as a security precaution.

    Installing Homebrew through Terminal partition for partition recovery on macOS

  3. Wait for the command to finish and hit Enter again after the review screen below.Confirming Homebrew installation for partition recovery on macOS
  4. Wait for Homebrew to install (it may take a minute or two).Wait for Homebrew to install for partition recovery on macOS
  5. After the Homebrew installation is complete, install TestDisk using the command below.
    brew install testdisk

    Install TestDisk for partition recovery on macOS

  6. Run TestDisk by entering the command below.
    sudo testdisk

    Once TestDisk is up and running, you’ll be prompted to decide whether to create a log (recommended) or not.

    Run TestDisk for partition recovery on macOS

  7. Select the drive you want to scan as well as the partition table type. Then choose to analyze the current partition structure, search for any lost partitions, and press enter to start the Quick Search.Select the drive in TestDisk for partition recovery on macOS
  8. Check to see if your missing partition is listed in the available options after Quick Search is complete. If it is, highlight it and select the Write option to save it. If not, you can choose the Deeper Search option for a more in-depth scan.Look for the missing partition in TestDisk for partition recovery on macOS

Case #3: Repair Your Damaged Mac Partition

If your Mac partition is damaged rather than deleted or lost, you can use Apple tools on your computer by default, namely Disk Utility. Rather than helping you recover a lost partition on a Mac, this technique can repair that partition instead.

To repair your damaged Mac partition:

  1. Open up Disk Utility. You can do so by locating it in Finder > Applications > Utilities. And of course, you can also simply search for it on Spotlight via the menu bar or by pressing Command + Space. If your damaged partition is on your startup disk, you’ll first want to restart your computer in macOS Recovery mode.Window showing where Disk Utility is in Applications
  2. Choose your damaged partition and click First Aid. If your partition contains multiple volumes, you’ll want to repair the volumes one by one first using this same process. After the volumes are repaired, then attempt to repair the partition as a whole.Window in Disk Utility showing partition button for partition recovery on macOS
  3. Confirm in the popup window and then follow the onscreen instructions.Window showing the First Aid process for partition recovery on macOS
  4. Once the process is finished, click Done. That’s it!

Bonus: Rebuild a Corrupted HFS+ Catalog Directory

Unfortunately, Disk Utility won’t be able to solve every problem related to your disk. For many, that might mean they’re stuck with an HFS+ catalog directory that’s still corrupted after following the above steps for partition recovery on macOS.

If you find yourself in this situation, it’s time to look to a third-party app. And once again, Disk Drill is a great choice here. This free software actually has a built-in tool specifically for this situation—Rebuild HFS+ Catalog File.

With this Disk Drill function, you can even write the recovered directory right onto the damaged disk. That means you don’t have to have the extra free space to mount a virtual disk image before going through the rest of the recovery process. It’s a time-saver to be sure.

Using Disk Drill’s Rebuild HFS+ Catalog File function is easy too.

To rebuild a corrupted HFS+ Catalog Directory:

  1. Startup Disk Drill like normal.Icon for Disk Drill, a Mac partition recovery tool
  2. You’ll be able to tell right off the bat if you need to rebuild an HFS+ catalog directory because Disk Drill will tell you so. You should see an icon like the one below next to your corrupted drive. All you have to do is click the Rebuild button, and Disk Drill gets to work.Rebuild button on Disk Drill when you recover a deleted partition on a Mac
  3. After it’s done scanning, you’ll be able to see a preview of the rebuilt file directory. Make sure it looks like you expected before proceeding. Once you have, you can choose Rebuild to rebuild the directory right onto the existing drive. You can also select Found Mount Items as Disk if you prefer to mount the rescued files to a virtual disk image.If the preview does not look correct, you can choose Back to try another recovery option.

FAQ

Generally, most users won’t have a need for partitioning their Mac hard drive. But there are some circumstances where partitioning your hard drive can come in handy.

  • If you want to run multiple operating systems on the same machine.
  • If you want to streamline your backup plan by separating key personal files from system files.
  • If you want to test out a new OS without having to uninstall your original.

However, it’s worth mentioning here that for users with an APFS file format (default for macOS 10.13 and above), you shouldn’t partition your drive in most cases. Instead, you can create volumes that achieve the same effect but also offer flexible space management.

If you cannot partition your hard drive (e.g., greyed out confirm option), you’ve likely run into one of two problems.

  1. You Don’t Have Enough Space – The amount of free space required to partition your hard drive must be enough to host a secondary operating system. If this is the problem, you’ll likely see an error message like the one below. To fix it, free up more space on your drive (aim for 50GB free if you can).Warning showing insufficient space for partitioning your Mac
  2. Your External Drive Partition Format Is Not macOS Compatible – Your Mac is likely compatible with APFS, HFS+, and MS-DOS (FAT)/exFAT file types. If your external drive uses another format type, it can’t be partitioned or even read on your Mac. Reformat the drive in the appropriate format to fix this problem.
You certainly can. All it takes is:

  1. Locating Disk Utility in Finder > Applications > Utilities. You can also search for it on Spotlight via the menu bar or by pressing Command + Space heading to Disk Utility.
  2. Clicking Partition.
  3. Selecting the partition you want to delete from the pie chart and clicking the delete button (–).
  4. Clicking Apply and then clicking Partition.

Always back up your data before you begin, as all data on that partition will be erased.

Conclusion

A corrupted, deleted, or lost partition may feel like the end of the world at first.

But there are a few tools and tactics like the ones outlined above that you can use to recover your data and avert total disaster. And when used in conjunction with a multifaceted backup recovery strategy, you can rest easy knowing you and your data are protected.

Alex Thompson has spent his career turning complex topics of all kinds into digestible content that keeps readers engaged. He’s covered everything from cybersecurity and cryptocurrency to light bulbs and golfcart drag racing (no kidding). When he isn’t writing, he’s going for a run, watching bad TV, or walking his beagle.
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