Delete local TimeMachine snapshots

Your Time Machine backup disk might not always be available, so Time Machine also stores some of its backups on your Mac. These backups are called local snapshots. Local TimeMachine snapshots take a large amount of disk space. This space is listed as purgeable in disk info, but cannot be actually used until the system decides to free it up. You can list all local backups with:

tmutil listlocalsnapshots /

Then delete one by one, with follow command:

sudo tmutil deletelocalsnapshots <snapshot date>

You can lists all snaphosts and deletes all of them in a loop:

for d in $(tmutil listlocalsnapshotdates | grep "-"); do sudo tmutil deletelocalsnapshots $d; done