macOS Big Sur Not Enough Free Space

I have exactly the same issue.

Hi,

Are you using Time Machine, If so you may have local snapshots of them store locally on your Mac. (This is the issue I faced when installing)

Try this
Quoted from https://support.apple.com/en-gb/HT204015
"If you want to delete local snapshots manually, turn off Time Machine temporarily:
Open Time Machine preferences from the Time Machine menu  in the menu bar. Or choose Apple menu  > System Preferences, then click Time Machine.
Deselect “Back Up Automatically” or click the Off/On switch, depending on what you see in Time Machine preferences.
Wait a few minutes to allow the local snapshots to be deleted. Then turn on Time Machine again. It remembers your back-up discs."

That that does not work try deleting it manually in the terminal.

Type tmutil listlocalsnapshots /
You should be presented with something like this com.apple.TimeMachine.2020-06-01-002010 (the number will be different)
If this appears
Type sudo tmutil deletelocalsnapshots 2020-06-01-002010 (substitution the ID presented before)

Hope this Helps

Same issue here.

In the terminal:

tmutil deletelocalsnapshots /

That will free up the space you need.

For me, using macOS 10.15.6 beta on a MacBook Air, the answer by @teddy06550 was close, but the actual example was simpler. Weird. Teddy's second command failed:

Code Block bash
Air2:~ jk$ sudo tmutil deletelocalsnapshots 2020-06-15-002518.local
Password:
2020-06-15-002518.local is not a valid disk

So instead I did what it implied I needed to do:

Code Block bash
Air2:~ jk$ sudo tmutil deletelocalsnapshots /
Deleted 2 Time Machine local snapshots for volume group containing disk '/'
com.apple.TimeMachine.2020-06-15-002518.local
com.apple.TimeMachine.2020-06-22-183122.local

and, voila…

Code Block bash
Air2:~ jk$ tmutil listlocalsnapshots /
Snapshots for volume group containing disk /:
Air2:~ jk$

No more local backups.

Side note: Before doing this I had 89 GB available, 73.33 GB purgeable and the installer said I had only 16 GB available and needed 34 GB more. After doing this, I have 159 GB available, 73.33 GB purgeable and the installer says I have 86 GB available and it is ready to go. Well, indeed 159-73=86. So it looks like the space used by Time Machine and the space used by "purgeable" are different issues.

By the way, think I know how I got so much in Time Machine local backups. During the last few months, I have created a half dozen or so screencast videos using Screenflow, which is an ( excellent) document-based app. Some of them may have been left dangling because I did not want to save them and force quit. That may or may not have made the problem worse.

Anyhow, thanks very much to Teddy for the tmutil tip. I think this is a bug – that Time Machine local backups can use such a huge amount of space with absolutely zero visibility. Am I wrong or should I file a bug? Or maybe is this fixed a Big Sur?

Or you can open Bootcamp it will free up space.

I deleted parallel and the virtual windows to free space but macOS didn't free up the space until I followed the method bellow from a link That link and I regained 130 gb
Open the Terminal application in Applications/Utilities. What we need to do is to start making a file that will grow until the disk is full. So enter the following into the Terminal window:
dd if=/dev/zero of=~/stupidfile.crap
The command will create a file called stupidfile.crap in your Home directory and fill it with zeros. It will continue to grow, first at a fast pace, but as the disk get’s close too full, it will become slower and slower. But hang in there. During the creation of the file, you will get a lot of warning messages that the disk is full. Just leave it there, because if you close it, it will reappear after a while.
When the Terminal window command ends with the message “No space left on device,” the disk is full, and mission accomplished. Mac OS should now have removed all the Purgeable space from the drive. So all that is left is to delete the file stupidfile.crap inside your home directory.
Don’t forget to empty the trashcan to regain the space.

The same thing happened to me. I had more than 145 GB free space but my mac said 18 GB is available and additional 33 GB is required whenever I tried to install macOS Big Sur. I spend hours trying in so many ways that all failed. Thanks to Teddy. I followed his advice. I did deselect Back up automatically in time machine and typed tmutil listlocalsnapshots / in terminal. Then, I tried installing and It worked perfectly. Such activities should be easy and friendly so as anyone can install/upgrade software in a simple way. APPLE need to solve this issue.

I'm definitely no "developer" but I found a much simpler solution that seems to be working so far. I transferred the "Install macOS Big Sur Beta application to an external hard drive, deleted the app from my computer, then ran it directly from the EHD and still selected to install the OS onto my Macintosh HD disk. I still have 12 minutes until it finishes installing, so cross your fingers!

Just an update: After moving the Install macOS Big Sur Beta application to my external hard drive, it downloaded just fine. No issues with storage. I'm happy to report that I'm running Version 11.0 Beta as we speak.

Teddy is a genius!

I was struggling with the exact same situation. No matter how much I deleted off my Hard Drive - it didn’t affect the free space listed in the installer.

I also moved the installer to an external HD and still no luck.

Trying Teddy’s method, disabling Time Machine and then using Terminal to remove the snapshots worked a treat. Suddenly the free space required on the installer was dropping and allowed me to install onto Macintosh HD! Thanks for your help.

This is probably a superrrrrrrrrr late reply, but I'm trying out the beta program today, and it said not enough space, so i checked and some volume container took up 210gb, i only have 256gb and i found out if you type

diskutil eraseVolume APFS Blank /dev/disk1s1

that into terminal, it will erase it for you

Move Xcode to an external drive.. install big sur then move it back to your Mac drive.. worked for me 😀

Followed advice from teddy06550 and it worked… the second time. Thanks!

I own a MacBook Pro 13 inch with 128gb and this update was stressful. I had to move basically everything on Mac to an external ssd including the Big Sur installer. Whatever I moved the storage was not updating. I almost gave up but then I restarted my Mac and finally it showed there was enough space available. The update installed and took about 30minutes. After the update there was more storage available. Hope this helps someone!