How to restore Mac OS after installing Linux I'm going to install Linux on a Macbook Air (from ~2013), and I plan on replacing the entire contents of the hard disk (OS, recovery partition, etc).

If I want to restore Mac OS, will Internet Recovery work? Do I really just need to hit Command+Option+R during boot? Should I back up something to make restoring easier?
To answer the questions asked, yes.

However, have a look at How to reinstall macOS and About macOS Recovery.

That said, personally I'd create a USB macOS Installer and set it aside for when you want to reinstall. Have a look at: How to create a bootable installer for macOS

Also, dont forget to make proper backups of your data before formatting the HDD/SSD. You might even want to have a Time Machine backup. Have a look at: How to use Time Machine to back up or restore your Mac