> Not enough free space to migrate
I’m trying to migrate from a MacBook Pro 2013 to 2017. The older has 160GB free on internal storage, but Migration Assistant says there’s insufficient space on the newer machine. Why, and what can I do?
Estimates of free space in APFS are approximate and can sometimes be inaccurate. Most reliable is Disk Utility, and the Finder is often less reliable. Least trustworthy is the Storage tab of About This Mac, which can be wildly incorrect. There are other factors which change how much data needs to be copied. iCloud storage is one culprit, especially when you allow Optimize Mac Storage. That lets your Mac “evict” many files in iCloud Drive so they take almost no local space, but when you migrate them to a new Mac they may be downloaded and occupy full space.
As you can’t appeal decisions made by Migration Assistant, your choices are to proceed with the migration, but reduce the files that you want copied across, or to stop and perform some housekeeping. Once you’ve reduced the amount to be transferred, this should also be quicker. When you exclude items from the migration, try to select those which could be copied manually if you do end up with sufficient space on the newer Mac.