Out of curiosity, I'm wondering where in the file system Time Machine stores its local backups/snapshots.
4 Answers
The actual data is stored in a hidden directory called .MobileBackups
at the root of the volume.
There is a special virtual filesystem type called mtmfs
which translates the raw data in these hidden directories into a virtual Time Machine drive which is automatically mounted on /Volumes/MobileBackups
This mechanism of storing local backups existed on HFS format file systems and is no longer how things work on APFS Macs. Snapshots now are built in to the filesystem as opposed to needing to make “shadow copies” of files in a new location, the “shadow copies” are of the whole disk state.
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1Not sure if this works for El Captain anymore, I can't find anything at least. I cd'd into volumes and did a ls -a (which shows all files, so including the hidden ones, in a directory) which gave nothing, tried this in both recovery and normal boot mode. Did the same thing for the root volume.– rien333Jan 23, 2016 at 20:46
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I can still see it on my El Capitan laptop (10.11.4).
/Volumes/MobileBackups
exists and has aBackups.backupdb
directory inside it. It's still amtmfs
mount according tomount
, and I'm pretty sure the actual data is still stored in/.MobileBackups
but the format has changed. May 14, 2016 at 16:07
Under the new file system in High Sierra (Apple File System (APFS)), this it is different. You can see what is considered the "local backups" via command line like this:
sudo tmutil listlocalsnapshots /
Ones that are listed as "(dateless)" will cause all sorts of problems:
com.apple.TimeMachine.2017-12-23-090037 (dataless)
so you can delete any backup by command line like this (deletes the one listed above, note only date used in reference):
sudo tmutil deletelocalsnapshots 2017-12-23-090037
Note that in my latest problem with macOS, the "bird" process was eating up egregious amounts of CPU. It was suggested that dumping backups that were damaged (damaged, who knew?) would help.
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2This should be the accepted answer. This is the correct practice. May 6, 2020 at 12:16
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1Note: if you want to see where they are mounted, take the names that are listed and do:
sudo find / -name "com.apple.TimeMachine.*" 2> /dev/null
(or something similar) Jul 12, 2021 at 12:40 -
This also solved another problem with broken timemachine backups apple.stackexchange.com/questions/466571/… The one thing is that when I ran listlocalsnapshots my filenames have .local appended, but you need to cut that off when you run deletelocalsnapshots, so just with the numbers as shown above. Nov 18 at 18:27
They are stored on your hard drive in the folder entitled:
/Volumes/MobileBackups
Note: This answer is now dated and incorrect for current MacOS versions. It was accurate for MacOS Lion, but has changed since that time. See other answers for updated locations.
On Catalina they seem to be in:
/Volumes/com.apple.TimeMachine.localsnapshots
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Yes, this is where the snapshots can be mounted. They are stored in the filesystem and may not be visible until they get mounted by the system or Finder or a command line tool.– bmike ♦Oct 1, 2020 at 18:01
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1They probably do get automatically mounted by the OS, since I at least haven't done anything to mount them and they still appear.– ruoholaOct 1, 2020 at 18:03
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