I want to upgrade from Big Sur version 11.6, but my computer tells me I can't install Monterey because I need an extra 10.5 GB of storage. How do I achieve that?

• Before you do anything backup your main drive.
• Are you using iCloud syncing? If not turn it on to store photos etc in the cloud.
• If you don’t want to use iCloud move photos to an external drive
• Open About this Mac, click on Storage then Manage, this will help get rid of some files.
• Uninstall any apps you are no longer using.
• Delete any files from your Download folder which you can downloaded from a web site if needed in the future.
• Don’t be tempted to install cleanup apps as these can cause bad things to happen especially when upgrading the OS

I would have just assumed that the new iOS (Monterey) would be about the same same as the older one (Big Sur) and it would have just taken over the storage space.

It is about 1-2 GB bigger, but it needs the extra space to move things around while it installs.

You need to clear some space in your drive. Get yourself an external drive and copy off some stuff.

Also: do not upgrade without having a full backup.

I have an extra 77 GB. And the upgrade to Monterey seems to be fine. Is the Tapsnake virus due to the upgrade?