After the next backup, or when the disk space runs low, the local snapshots are automatically removed by macOS. The local snapshots can pile up to as much as 80% of disk space. It keeps making local snapshots when the persistent TM storage is not available.
Most likely the space is taken by Time Machine. If urgency is not specified, the default urgency will be used. When purge_amount and urgency are specified, tmutil will attempt (with urgency level 1-4) to reclaim purge_amount in bytes by thinning snapshots. Thin local Time Machine snapshots for the specified volume. On older MacOS releases, it was possible to disable the local snapshot feature entirely, this doesn’t seem to be the case with High Sierra – but it does appear to be possible to force an immediate purge of local snapshots with the following command: sudo tmutil thinLocalSnapshots / 10000000000 4įrom the tmutil manpage: thinlocalsnapshots mount_point I found an answer in a blog that worked for me:Īpple state that they automatically remove local snapshots when disk space is low, but their definition of low is apparently only 5GB of free space remaining – not really much free working space in 2017 when you might want scratch space of 22GB for 1 hour of 4k 30FPS footage. I recently ran into this - on my 500GB SSD, my free space was only 5% where I expected more like 75%.
