Did you now that you can take a snapshot of your Mac at any point in time, using a single Terminal command?
As soon as you upgrade to macOS High Sierra, your Mac will switch from HFS Plus to a new file system, known as APFS (Apple File System). One of the more notable features of this brand new file system, is its ability to take snapshots.
Similar to Windows restore points, an APFS snapshot is a read-only copy of the state of your Mac at the time when that snapshot was taken. Starting with High Sierra, your Mac will automatically create a snapshot before installing any macOS updates (assuming that you’re installing the update on a boot drive that uses APFS). You can also create snapshots manually, so if you ever need to return your Mac to a previous state, you can simply restore the relevant snapshot.
To ensure you always have something to restore in case things go wrong, you should try and get into the habit of taking a quick snapshot before performing any major or experimental changes.
In this article, I’ll show you how to manually take a snapshot of the current state of your Mac, without having to install any additional software.
Create your first Apple File System snapshot
Snapshots operate independently of Time Machine, so you can create and restore snapshots without setting up Time Machine (although you should still create complete Time Machine backups in addition to snapshots). Since snapshots are saved to your Mac’s local drive rather than your Time Machine drive, they’re particularly useful when your Time Machine backup disk isn’t available, for example if you’re travelling and have left your backup drive at home.
You create a snapshot using macOS’ built-in Terminal application:
- Open a Finder window and navigate to ‘Applications > Utilities.’
- Double-click to launch the Terminal application.
- Type the following command into the Terminal window:
tmutil snapshot
- Press the ‘Enter’ key on your keyboard.
If the snapshot was created successfully, the Terminal will return the following message:
“Created local snapshot with date: ((date)).”
You can view a list of all the snapshots that are currently available on your local drive, by typing the following command into the Terminal:
tmutil listlocalsnapshots /Volumes/
Then, press the ‘Enter’ key. This will return a list of all your snapshots, complete with their timestamps.
Similar to Time Machine backups, if macOS is running low on space then it’ll start replacing older snapshots with newer ones, beginning with the oldest snapshot. If you regularly create snapshots, then you should pay attention to how much storage space is available, to make sure macOS doesn’t start deleting these snapshots.
To check how much space is currently available on your Mac.
- Select the ‘Apple’ icon from your Mac’s menu bar.
- Click ‘About This Mac.’
- Select the ‘Storage’ tab. The white bar at the end of the graph represents the amount of space currently available.
Restoring a Snapshot
To return your Mac to the state it was in when you created a particular APFS snapshot:
- Boot into Recovery mode by turning your Mac off, and then restarting it while holding down the ‘Command+R’ keys. Release these keys as soon as the Apple logo appears.
- Once your Mac has booted into Recovery mode, select ‘Restore from Time Machine,’ and then click ‘Continue.’
- Recovery Mode will display a list of all the connected disks that contain Time Machine backups or snapshots. Select the disk that contains your snapshot (this is typically your Mactonish HD boot drive) and then click ‘Continue.’
- Find the snapshot that you want to restore, and then click ‘Continue.’
- Read the onscreen warning, and click ‘Continue’ if you’re happy to proceed.
- Recovery Mode will now restore this snapshot. Once this operation is complete, your Mac will reboot automatically.