Free Up Drive Space on macOS
Updated: Mar 21, 2019
Over the last year, I’ve been playing the “free up space” cat and mouse game on my MacBook Pro. I’ve been teetering on only having 10 to 20GB free requiring a constant purge of older files and unused apps. But regardless of how much I removed, when I would look at my Disk Utility, it would only show having the 10 to 20GB free. Tonight, I decided to try and figure out why, regardless of how many files I removed, I couldn’t make a dent in the available space. It came to a head when I removed a 69GB VM Ware Fusion Image. Much to my surprise, after removing the file and checking the available space in the Disk Utility, it still only showed 20GB available. Luckily, I came across the blog post “ MacOS High Sierra unable to free disk space”. In the post, the author explains that the issue in this case is related to the fact that Time Machine retains local snapshots of the back ups resulting in significant amount of storage loss. Apparently, the files will be purged when space is needed, but according to the author this won’t happen until you are down to your last 5GBs. As it turns out, there is a utility that will force a shrinking/purge of the local snapshots. Executing the following command from a Terminal window does the trick (see screen shot):
sudo tmutil thinLocalSnapshots / 10000000000 4
After running, it Disk Utility reported I had over 100GB of storage available Problem solved.