How do I clear the purgeable area on my disk? I cleared space on my disk by deleting files and emptying trash. But, I am unable to make use of the space that I freed up. That is, as you can see the disk reports 142 GB as Available with 83 GB of that as purgeable.



So I should have plenty of space to to copy over a 70 GB file onto the disk. Yet when I try I get an error stating "Not enough disk space to copy", like the following image shows:



How do I clear out the purgeable space to make it truly available for use?

I've tried rebooting in the hopes that a restart clears out the purgeable area, but had no change trying that.
You can create a huge file that will force macOS to clean purgeable files to free you space. Do do so, type this command in a terminal:

dd if=/dev/zero of=~/hugefile bs=15m


It will create a file called hugefile in your home folder, which you can check the size with Get Info and stop when it's big enough for you, using ControlC. Or you can simply let it run until you are out of space in the disk and things start to stop working.

This command takes a long time to allocate the memory, you can also stop it when it's 5~10GB and duplicate the file CommandD to create copies and speed up the process.

Then, you just need to delete the files, obviously.

In your case, you already have the file you want to copy, so you could split it into 50 GB chunks and copy one chunk over. Then let the system purge files and repeat. Once you have all the data over, you can combine them - adding the second file to the first, deleting the second file, etc...


How to merge files after using split command from terminal?


The main problem is that “purgeable” space is not one monolithic item - it is potentially local time machine or filesystem snapshots, cached data, derived data, iCloud photos at full resolution that will be downsampled as you start to get closer to no free space available.

The system will self correct if you can bring the data over in two pieces in your case, or in n-pieces in the general case.