Backup & prep

The work to do before installing. None of it is hard. Skipping any of it is how an exciting weekend becomes a stressful one.

1. Take a Time Machine backup — then verify it

Plug an external drive into the Mac, open System Settings › General › Time Machine, add the drive, let it finish. Depending on how full your disk is, this takes anywhere from twenty minutes to several hours.

This is your road home. If Linux turns out not to be for you, macOS reinstalls and the backup restores on top — you're back exactly where you started.

Verify the backup before continuing

Click the Time Machine icon in the menu bar, choose Browse Time Machine Backups, pick a recent snapshot, and open one of your real documents from it. If you can read it, the backup is real. If you can't — fix that before doing anything else. A backup you've never restored from is a backup you don't have.

2. Sign out of Apple ID and disable Find My Mac (T2 only)

This step matters on T2 Macs

T2 Macs have Activation Lock through Find My. If you wipe the disk while Find My is still enabled, the firmware can refuse to boot anything until you sign in again with your Apple ID password — the same as on a stolen iPhone. People have ended up locked out of perfectly good hardware. Don't be one of them.

On the Mac, before installing:

  1. System Settings › Apple ID › iCloud › Find My Mac: turn it off. Enter your Apple ID password when prompted.
  2. System Settings › Apple ID: scroll to the bottom, click Sign Out.
  3. If you're keeping macOS in a dual-boot, you can sign back in after the install. If you're replacing macOS entirely, you don't need to.

Pre-T2 Macs don't have this lock and you can skip this step.

3. Decide: dual-boot or replace macOS?

Replace entirely. Cleaner, more space, fully committed. If you ever need macOS back, reinstall from Apple's recovery and restore from the backup.

Dual-boot. Keep both on the disk; hold Option at startup to choose. Smaller commitment, easy fallback during the first weeks.

For a first-time switcher, dual-boot for the first month is worth the small extra hassle. Once you've gone three or four weeks without booting macOS, reclaim the space.

If dual-booting, free up disk space now: aim for at least 60 GB, ideally 100 GB. About This Mac › More Info › Storage Settings shows what's eating room.

4. Turn off FileVault — and wait for it to finish

FileVault encrypts the macOS disk and has to be off before the installer can resize or read it. System Settings › Privacy & Security › FileVault › Turn Off. Enter your password.

Decryption runs in the background and can take an hour or two on a large disk. macOS shows a progress bar directly under the FileVault toggle while it's working — wait for the bar to disappear. If you start the install before decryption finishes, the installer will fail and you'll lose time troubleshooting.

5. Have these ready

Tip: if Wi-Fi doesn't work in the installer

This can happen on older MacBooks (Broadcom firmware) and on T2 Macs that haven't had their firmware extracted yet. The cleanest fallback is USB tethering from a phone: plug the phone in, enable Personal Hotspot, and the connection shows up as a wired Ethernet device in Linux. Both Fedora and Zorin handle it without configuration. Saves you from buying a USB Ethernet adapter.

6. Now open the install page

Plan for a quiet two hours with no interruptions. Not because anything's dangerous — because rushing is how you skip a step.