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One of the biggest problems users have found after upgrading to macOS Catalina and Big Sur is that their Mac is suddenly running low on disk space.

If you’re constantly seeing a warning pop-up that “Your startup disk is almost full” and “To make more space available on your startup disk, delete some files” then you’ll know how frustrating this can be.

The main reason for this is that Catalina and Big Sur take “snapshots” of macOS to backup your system but these snapshots take a lot of valuable storage space.

It’s very hard to find these on your Mac but thanks to DaisyDisk, it’s really easy to find and delete the ones you don’t need.

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Using a disk storage utility like Daisy Disk is now almost essential on macOS because since the release of of macOS 10.13 High Sierra was that, Apple switched to the new APFS file system for Macs with SSD drives.

APFS basically balances file space more “intelligently” on your Mac particularly when it comes to Time Machine snapshots and backups.

Although APFS can help manage disk space more efficiently, it can also be something of a curse because it actually makes it harder to accurately check storage on your Mac and recover disk space being hogged by local snapshots.

If you’ve deleted some large files on your Mac and yet still find that it hasn’t freed up any disk space, it’s probably due to these snapshots.

macOS will eventually delete them but only in its own sweet time which isn’t convenient if you need that storage space immediately.

Here then is an easy way to fully recover storage space on your Mac including High Sierra, Mojave, Catalina and Big Sur.

  • Download and run DaisyDisk. The developers behind DaisyDisk are one of the few to have studied in-depth the new APFS system. DaisyDisk has long been the best utility to find large files or recover disk space on Mac but has now been updated to find and delete snapshots and “purgeable space” that is no longer visible in macOS. In previous versions of macOS, going to About This Mac > Storage clearly showed the amount of purgeable space on your Mac:storage space macos - macos sierra disk utilitySince High Sierra however, Purgeable space is no longer displayed in macOS. It is simply factored into System files which isn’t very helpful and makes it appear that macOS system files are taking-up a huge chunk of hard drive space as you can see below.recover disk space mac - mojave purgeable files gone Purgeable space mainly consists of local snapshots which your Mac makes periodically. It also contains sleep images, caches and temporary system files. DaisyDisk can locate and delete these files instantly.
  • When you complete a scan of your hard drive with DaisyDisk, you’ll see a sector called “Hidden space”. If you expand that, you will see “Purgeable Space”.

low disk space mac - daisydisk purgeable space

Although macOS will eventually delete these purgeable items on its own, it may take some time. Daisy Disk however allows you to force a purge of the files so that you can reclaim this space immediately.

Drag the purgeable space item into the DaisyDisk Collector and it will forceably delete it.

recover disk space on mac - daisydisk purgeable space

Note that this may take a few minutes to complete depending on the size of the file.

  • When finished, DaisyDisk will recalculate the new amount of purgeable space. Note that it may not delete everything because macOS may not be able to release all of it and it will also immediately start rebuilding temporary files as soon as it’s deleted.

So if you’ve been struggling to recover disk space on your Mac especially on Catalina and Big Sur, it’s probably snapshots and purgeable files that are the problem.

Although macOS no longer allows you to find and delete space hogging things local snapshots, DaisyDisk provides a quick and easy way to delete them.

Remember though that the best way of making sure you maintain plenty of free disk space on your Mac is to backup and remove large files that you don’t regularly need to an external hard drive.

If you have any other problems recovering storage space on your Mac hard drive, let us know in the comments below and we’ll try to help.

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One Response

  1. Gaz

    so to save space I have install a piece of software that will take up space?
    what about if, like me, it won’t let me install or run software As IT SAYS I HAVE NO SPACE!!!


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