I keep getting the message "there is not enough free space on the selected volume to upgrade the os" when trying to upgrade from Mac OS Catalina (10.15.7) to Big Sur. Currently I have 35.7 GB available of 121 GB on my disk and I apparently need 11.8 more GB for the upgrade.

I've looked for help online but I can't seem to find a working solution. I've cleared up a lot of storage (apps, large files, caches) to attain my free 35 GB, and other things I tried include:

  • tmutil listlocalsnapshots / in order to see and delete Time Machine backups, which yields only Snapshots for volume group containing disk /:. Don't know what to do here.

  • sudo /Applications/Install\ macOS\ Big\ Sur.app/Contents/Resources/startosinstall --agreetolicense --nointeraction --forcequitapps to directly install from the terminal. But this displayed sudo: /Applications/Install macOS Big Sur.app/Contents/Resources/startosinstall: command not found

I don't know how I would be able to upgrade to Big Sur. Is there something that I haven't tried yet, or is faulty in my approach? I would greatly appreciate any help/guidance. Thanks!

(If it helps to know, my Macbook Air is from 2019, with the 1.6 GHz Dual-Core Intel Core i5 processor.)

  • 1
    Please post the output of diskutil list and df -h.
    – lhf
    Oct 3 at 0:29
  • @lhf Thanks for replying. The output for diskutil list is shown here: imgur.com/dKwUlgu and the output for df -h is imgur.com/mzS9SVM (linked as images for clarity)
    – AdiBak
    Oct 3 at 0:47
  • df says that you have 21GB available, not 35.7. But you need some 35GB to install Big Sur.
    – lhf
    Oct 3 at 1:25
  • 1
    I see, so is it possible to upgrade to Big Sur by freeing more space? (although 14 GBs is a lot to empty).
    – AdiBak
    Oct 3 at 1:38


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