Hyperspace Frees Up Disk Space Without Deleting Files
Developer, writer and podcaster, John Siracusa, has a new app you
should try out if disk space on your Mac is starting to become scarce.
I'm not convinced that anyone, anywhere, including Cupertino, truly understands the relationship between the disk space you actually have on your Mac and what the system reports. Cloud storage totals show what's in the cloud, not on your hard drive. Then there is the whole purgeable space concept. Another factor that contributes to the mystery and one that I just learned about is what happens on AFPS formatted drives when you duplicate a file. I'll let the legendary Mac developer, John Siracusa, explain:
Today, most Mac users don’t even notice that using the “Duplicate” command in the Finder to make a copy of a file doesn’t actually copy the file’s contents. Instead, it makes a “clone” file that shares its data with the original file. That’s why duplicating a file in the Finder is nearly instant, no matter how large the file is. Despite knowing about clone files since the APFS introduction nearly eight years ago, I didn’t give them much thought beyond the tiny thrill of knowing that I wasn’t eating any more disk space when I duplicated a large file in the Finder. But late last year, as my Mac’s disk slowly filled, I started to muse about how I might be able to get some disk space back. If I could find files that had the same content but were not clones of each other, I could convert them into clones that all shared a single instance of the data on disk. I took an afternoon to whip up a ...scrip... to see how much space I might be able to save by doing this. It turned out to be a lot: dozens of gigabytes.
There are plenty of Mac apps that will save disk space by finding duplicate files and then deleting the duplicates. Using APFS clones, this app can reclaim disk space without removing any files.
If you have technical questions, there is extensive documentation on Siracusa's blog - Hyperspace
Siracusa went on to convert the script he wrote into a native Mac app, written in Swift. You can get it from the App Store for free and run it against your Mac's file system to see how much disk space you can reclaim. If it's a significant amount, you have several subscription and purchase options:
- $9.99 a month
- $19.99 a year
- $49.99 lifetime