Disappearing Disk Space?! 10 Step Fix

Today, I left my Mac alone for a few hours. When I come back, I am confronted with messages telling me that I don’t have enough disk space left.

A quick check of my available disk space using Finder reveals that I only have 200mb of free space left on my 115GB SDD.

Wait, WHAT?! I left my computer and it had 50 GB free. How can 49.5GB just magically appear on my hard drive?!

I couldn’t even DOWNLOAD that much during the time I was gone.

So I decided to find out what was taking up so much space using a wonderful free application called GrandPerspective (review here, what a wonderful app if I may say so myself) and decided to try and find out what was taking up so much space. Here’s what the result looked like:

WHOW THERE! What is all that green that’s taking up half of my hard drive?

A quick hover reveals that these are “swap” files that live in a hidden folder that’s reserved for system use.

Swap files are spaces where application memory/files is held. It’s like a less random access version of RAM. And somehow, my computer had 50GB of it.

Here’s the fix:

  1. Shut down your computer. If necessary, just hold down the power button and force shut it down.
  2. Hold down the shift key.
  3. Press the power button while still holding the shift key.
  4. When the apple logo appears on screen, lift your finger from the shift key.
  5. A loading bar will now appear. Wait a while and it will eventually show the login screen. It will let you know that you are booted into safe mode.
  6. Don’t log in!
  7. press the Back button on the login window, then press Shut Down.
  8. Press the power button without pressing any keys.
  9. Wait for the computer to boot.
  10. Enjoy your spacious computer!

There ya go! It’s a simple fix for a near catastrophic problem.

To prevent this from happening, restart your computer every couple of days. That was probably my problem, as I haven’t restarted in about a week. Oops!

When you restart, you don’t need to do the safe boot, as it will still clear a large amount of the swap files and cache. This is more proof that it’s a good idea to restart now and then, preferrably daily!

A reboot a day keeps the swap files away!