Mac OS Big Sur cannot be installed on “Macintosh HD” I cannot get beyond this message. What have I done wrong / how can I fix it?
MacBook Pro Retina
Probably the most common reason for this is not enough disk space free. (There can be other reasons but free space is the most common one I have seen for this message.) Try emptying the trash and reboot. Click once on Macintosh HD and choose File => Get Info to see how much free space there is.
While the Big Sur Installer is typically 10-15 GB, it has to be expanded and ultimately as much as 35-40 GB may be required free space. In fact you will want a good buffer above that for free space since everything the computer does (including the install itself) will be extremely slow if the Mac is operating close to zero or little free space.
Common ways to save disk space: clearing out the Downloads folder, moving photo libraries to an external drive, deleting old and no longer useful iPhone backups and iPhone IOS upgrade files. Sometimes just searching for all files with ".dmg" in their name results in scores of large .dmg files that are no longer needed and can be deleted. OmniDiskSweeper (free) or DaisyDisk (not free) can analyze your disk and show you where your disk usage is.
How much free space do you have?
Probably the most common reason for this is not enough disk space free. (There can be other reasons but free space is the most common one I have seen for this message.) Try emptying the trash and reboot. Click once on Macintosh HD and choose File => Get Info to see how much free space there is.
While the Big Sur Installer is typically 10-15 GB, it has to be expanded and ultimately as much as 35-40 GB may be required free space. In fact you will want a good buffer above that for free space since everything the computer does (including the install itself) will be extremely slow if the Mac is operating close to zero or little free space.
Common ways to save disk space: clearing out the Downloads folder, moving photo libraries to an external drive, deleting old and no longer useful iPhone backups and iPhone IOS upgrade files. Sometimes just searching for all files with ".dmg" in their name results in scores of large .dmg files that are no longer needed and can be deleted. OmniDiskSweeper (free) or DaisyDisk (not free) can analyze your disk and show you where your disk usage is.
How much free space do you have?
Mac OS Big Sur cannot be installed on “Macintosh HD” I cannot get beyond this message. What have I done wrong / how can I fix it?
