How to use Time Machine and APFS snapshots on macOS

Time Machine setup guide

Step 1: exclude folders from Time Machine

Heads-up: excluded folders vary depending on use case.

Step 2: format Time Machine disk as “Mac OS Extended (Journaled, Encrypted)” using “Disk Utility”

WARNING: DATA ON TIME MACHINE DISK WILL BE PERMANENTLY DELETED.

Step 3: enable “Encrypt Backup Disk” and click “Use as Backup Disk”

Step 4: confirm encryption is enabled and enable “Show Time Machine in menu bar”

Encrypted

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Time Machine usage guide

Create backup

Click “Time Machine” menu bar icon and then “Back Up Now” or run tmutil startbackup.

Delete specific backup

Heads-up: use tmutil listbackups to list backups.

$ sudo tmutil delete "/Volumes/LaCie/Backups.backupdb/Sun’s MacBook Pro/2021-04-05-161636"
Deleting: /Volumes/LaCie/Backups.backupdb/Sun’s MacBook Pro/2021-04-05-161636
Deleted (43.5M): /Volumes/LaCie/Backups.backupdb/Sun’s MacBook Pro/2021-04-05-161636
Total deleted: 43.5M

Total deleted: 43.5M

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APFS snapshot usage guide

Create local APFS snapshot

$ tmutil localsnapshot
Created local snapshot with date: 2021-04-05-162425

Created local snapshot with date: 2021-04-05-162425

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List local APFS snapshots

$ tmutil listlocalsnapshots /
Snapshots for volume group containing disk /:
com.apple.TimeMachine.2021-04-05-162416.local
com.apple.TimeMachine.2021-04-05-162425.local

Mount local read-only APFS snapshot

Heads-up: use umount /tmp/snapshot to unmount snapshot.

Replace com.apple.TimeMachine.2021-04-05-162416.local with snapshot from List local APFS snapshots.

mkdir -p /tmp/snapshot
mount_apfs -s com.apple.TimeMachine.2021-04-05-162416.local / /tmp/snapshot
open /tmp/snapshot

Restore local APFS snapshot

Restart computer and press cmd+r to boot to recovery mode.

Select “Restore From Time Machine Backup”, then “Macintosh HD”, choose local snapshot, click “Continue” and “Continue” again to confirm.

Delete specific local APFS snapshot

Heads-up: use tmutil listlocalsnapshotdates to list local snapshot dates.

$ tmutil deletelocalsnapshots 2021-04-05-162416
Deleted local snapshot '2021-04-05-162416'

Deleted local snapshot '2021-04-05-162416'

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Delete all local APFS snapshot

$ tmutil deletelocalsnapshots /
Deleted 1 Time Machine local snapshots for volume group containing disk '/'
com.apple.TimeMachine.2021-04-05-162425.local

Deleted 1 Time Machine local snapshots for volume group containing disk '/'

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