What just happened to my hdd space after upgrade?

[Zillion]

Ok I have an Macbook Air 2014 11 inch 4GB 128MB flash. I am waiting on the new Macbook Pro since I gonna replace my i7 Windows PC for that as my horsepower.

So I upgraded the little machine. Before Sierra, it had 21 GB free space. Now it has 58 GB free space. I cleared the waste can before upgrade.

 

[steve62388]

Sierra now counts purgeable space as free space.

https://sixcolors.com/post/2016/10/purgeable-storage-sierra/