How to clear scratch disk when it gets full

You may have been told recently by your Mac that the scratch disk is full. This error can be caused by a few different reasons, but it’s likely a build-up in temporary files in which you have run out of space on your scratch disk. What does it mean? Your scratch disk is simply the space where cache and other virtual memory are stored – things like a previous version of your project.

These can build up because of force-quitting Photoshop and other programs regularly. Regardless of how it was caused, though, we need a way to deal with it. If the issue has been caused by simply having a full HDD, or RAM that’s got limited availability for Photoshop, then the “creating space on your disk and RAM” may be more relevant. In the meantime, let’s get rid of some cache.

Clearing the scratch disk

There are a few ways we can clear some space on the scratch disk. First and foremost, we can head to specific apps, like Photoshop, and clear cache (Edit menu in Photoshop, followed by Purge and All). However, we can simply clear some cache using third-party software that obliterates cache in a single click.

Next up to clear some space on the scratch disk is to delete your temp files. Again, this can be done on third-party software, or you can do it manually. You can search files ending in “.tmp” or you can head to ~/Library/Caches/ on the Go to Folder function.

You can also clear cache on the web browser specifically, for example, and other applications.

Creating space on your disk and RAM

This step is a more general one, to create space on the RAM and storage disk. The first step to clearing disk space is to head to About This Mac, followed by Storage. From here, you can see how much storage there is. If you have less than 15% of free space, this is likely where your issues are coming from. Begin by either deleting files you know you don’t need or clicking on the “manage” button to the right. From here, run through all four disk-clearing functions.

Next, open up the Activity Monitor by going on Finder, Applications, Utilities. The most intensive processes should be at the top (but you can sort by CPU usage if not). Quit the apps that are demanding but are not currently necessary. This should clear up some RAM too.

Preemptive measures

Some ways you can stop this from happening again is to properly quit programs instead of force quitting, or having the MacBook turn off randomly/instantly. You can also change the destination in which temporary files are stored, like changing the start disk within Photoshop settings.

Finally, you can change other settings such as auto-recovery saving. These are useful to have, but they’re undoubtedly what is contributing to using up your scratch disk storage. It’s not necessarily advisable, but it’s an option.

What is advisable if problems persist, is to reset Photoshop and other culprit programs in their entirety.