$ docker volume prune
...
Total reclaimed space: 224.4GB

Yikes...

@treyhunner
Almost my entire work Thinkpad's hard drive.

@simoncrowe yeah that was nearly half the space on my drive.

I had been clearing old files away because my drive has been filling up recently.

I realized today that my disk usage analyzer tool showed WAY less space used than actually made sense given the size of the drive and the available space... turns out I needed to run it with root access to see the mess that docker had been making.