I recently got a new SSD on Prime Day to replace one of my main hard drives. As this drive was included in Time Machine, I wanted the SSD to “adopt” the hard drive’s backup history. This way I could avoid recopying lots of data that was already backed up, which would also require pruning older snapshots.<\/p>\n\n
When you get a new Mac and want to adopt the old Time Machine backup, you want The command is documented as:<\/p>\n\n The -a<\/tt> tells it to find all the snapshots for that volume on the destination, not just the specific one that you pointed it to.<\/p>\n\n mount_point<\/em> is just the source volume’s path (in \/Volumes<\/tt>, not the device path).<\/p>\n\n snapshot_volume<\/em> is the destination within your Time Machine backup. The example shows this as being within the Backups.backupdb<\/tt> folder, but there’s no such folder when using an APFS destination. My first thought was to drag the latest snapshot from Finder into Terminal:<\/p>\n\n This does not<\/em> work. Instead, you need to find the path using Terminal:<\/p>\n\n It’s important<\/a> not to have any trailing slashes. And, also, it will fail if you use Previously:<\/p>\ntmutil inheritbackup<\/a><\/code>. When you keep the same Mac but get a new source drive, you want tmutil associatedisk<\/a><\/code>.<\/p>\n\ntmutil associatedisk [-a] mount_point<\/em> snapshot_volume<\/em><\/pre>\n\n
sudo tmutil associatedisk -a \/Volumes\/Aux \/Volumes\/.timemachine\/C2E8322E-A7EA-44F8-904F-3232671E1412\/2025-07-11-091237.backup\/2025-07-11-091237.backup\/Aux<\/pre>\n\n
sudo tmutil associatedisk \/Volumes\/Aux \/Volumes\/TM\\ 7\/2025-07-11-091237.previous\/Aux<\/pre>\n\n
-a<\/code> with an APFS destination. But I guess that’s OK because there’s only one .previous<\/code> folder to point it at, anyway, and APFS itself should know the chain of parent snapshots…<\/p>\n\n\n