OSX Notes

Here are my notes for upgrading OSX if you have a very tiny hardrive.

Major OSX Update

If it is a major update then:

Download Big Sur and write to external drive with

sudo /Applications/Install\ macOS\ Big\ Sur.app/Contents/Resources/createinstallmedia --volume /Volumes/MyVolume

Free up space with tips/ideas from this thread:

If you use docker and dont mind rebuilding your images run this:

docker system prune -a

Delete local timemachine backup snapshots: (Just reboot afterwards to actually see the freed up space):


sudo tmutil deletelocalsnapshots /

Then run Big Sur installer from installer PS: Remember to make a backup with time machine backup to external before upgrading just for in case