How to Remove All Time Machine Snapshots with One Command

Time Machine local snapshots cannot be turned off since macOS 10.13 and must be cleaned up one by one. This note introduces a very simple command that allows you to delete all Time Machine local snapshots at once.

First, execute the following command in PowerShell or Terminal (Bash)

sudo tmutil listlocalsnapshots /

Then you will see a window displaying your recent backups.

In macOS 10.15 Catalina, you can use the following command, which is very simple:

tmutil thinlocalsnapshots / 999999999999999 4

If you have a lot of backups, you may need to wait for several minutes, and then all of the Time Machine local snapshots will be cleared.

Ref: 清理 TimeMachine 本地快照的方法