I've never used Time Machine before and I pretty much know how backups work but I'm wondering if my system will work out of the box once restored from Time Machine backup?

I mean I have tons of stuff on my Mac and configuring it all once something goes wrong will take me days. I'm talking about my whole programming environment including multiple Docker images, databases, hundreds of npm packages, custom system files (like "hosts"), hundreds of Applications with custom settings, some games etc.

If I decide to backup EVERYTHING and things go south can I just grab a brand new MacBook, connect my external hard drive with TM backup and it will import EVERYTHING meaning it will work just like my system before crash?

BTW I'm using a standard external HDD.

  • Let’s make this one question per question. Feel free to comment with a link to the new question about versions if you can’t already find an answer here about restoring an older backup to a newer OS.
    – bmike
    Jun 24, 2018 at 21:51
  • I know this was long time a go, but how did that work? I have a disk that is not working well and a recent time machine backup. If I restore that, Do you think it will remember things like xcode project settings and keys ( or android? ) Thanks :) Jan 25, 2019 at 21:07

4 Answers 4


Time Machine by default backs up nearly everything in your macOS partition. It excludes log files, Spotlight indexes, caches, temporary files and trash (have a look: On OS X, what files are excluded by rule from a Time Machine backup?). The backup includes docker files, npm packages, your personal files etc. When the backup is completed, the hard drive will NOT be bootable, meaning that you can't run macOS from your Time machine backup.

You can restore from a Time machine backup without or after installing an operating system. If you restore without installing an operating system:

  • All the backup will be restored to your disk, including the operating system (for example Yosemite). [NOTE: If the Mac you are restoring to does not support the version of macOS in your TM Backup, it will still not be able to boot from the restore].
  • It can be done from either Recovery or Installation USB. No internet access is required.
  • After the backup is restored, everything will be exactly how it was while you were doing the backup.

If you restore after installing an operating system:

  • Only personal files and the files you select can be restored and will not restore the operating system.
  • Might not restore packages, system tweaks and files that are stored in directories other than traditional ones (for example "/MyApp/mysourcecode.cs" will not be restored by default).

If you think this contains misinformation, please comment because I never actually restored after an operating system installation.

  • 1
    I’m certainly not going to -1 answer, but Time Machine saves a list of excursions to each time it backs up. More generally, for the definition of whole system meaning everything, I’d review my answer to see the hundreds of locations and files that are excluded by rule in Time Machine. If you never use the command line or a shell, which is probably 90 to 95% of the Mac population - Time Machine has that majority covered with no risk whatsoever.
    – bmike
    Jun 24, 2018 at 21:24
  • @Monomeeth if I get a new or used MacBook it will most likely have the OS installed - I assume I can uninstall the OS and then run the backup restore? Jun 24, 2018 at 22:49
  • 1
    @Wordpressor Well, you could, but I'm not sure why you would in the event of a new Mac. In the event of a used Mac, if it was already prepared for sale as per Apple's recommendations, then you're also fine to keep it as is. If not, you would go through the process of reinstalling macOS first before restoring from your backup (unless you knew that the Mac fully supported the version of macOS in your TM backup and you wanted to use that version of macOS).
    – Monomeeth
    Jun 24, 2018 at 23:25
  • Time Machine does not back up installed screen savers by default! To fix this, run tmutil removeexclusion ~/Library/Screen\ Savers in Terminal.
    – SilverWolf
    Jun 25, 2018 at 13:17
  • 1
    From my own experience: it backs up /Applications, which is where most (if not all) applications are installed by default.
    – user255044
    Jun 25, 2018 at 13:45

No, time machine has several sorts of exclusions so it does not even back up everything, let alone restore everything. The good news, everything that gets backed up will restore to the same or newer OS.

You could review those and be safe knowing you’re set.

Or you could review each time you place things and verify you can restore them (or inspect they are not excluded).

 tmutil isexcluded /path/to/file

I would say you should probably have a clone backup to save your bacon and start with SuperDuper and Carbon Copy Cloner and not mess with disk utility (which can clone a drive) unless you really can’t make one of the purpose built tools to work for your budget and needs. Doing one bootable backup a month and any time you make major changes means you have two different backups and don’t need to update your clone every night (unless you really like that sort of thing).

Read up on either web site for the many potential benefits of a bootable backup, not the least being all files get copied.

  • 1
    SuperDuper and Carbon Copy Cloner are fantastic products. My personal recommendation is usually to use one of these and Time Machine as well. But then again, I also usually recommend to personal users they have two external backup drives that get swapped around weekly (with one always being kept off site), so I'm probably a bit on the extreme side of things.
    – Monomeeth
    Jun 24, 2018 at 22:29
  • @bmike I'm afraid I don't understand. I just want to know if I will be ready to work after restoring from the backup. If TM doesn't backup Trash contest, Cache or Spotlight indexes - I don't care as it changes almost nothing in this case. So I guess Monomeeth is right and I will be able to work perfectly fine after restoring? Jun 24, 2018 at 22:48
  • If you have a Time Machine backup then you can simply connect it and restore everything. @Wordpressor Even better, there is a hidden .exclusion.plist file as well as a migration log so you can see logs if you think something is missing and know if or why. The short answer is yes - a new Mac will take older backups just fine.
    – bmike
    Jun 24, 2018 at 23:11
  • 1
    +1 for Carbon Copy Cloner. It worked perfectly while Time Machine failed miserably. Time Machine tried to restore the system by applying many diffs one after the other, but one diff in the middle was defect so the whole process took hours, failed and started from the beginning. I had to write some scripts to recover some of the desired information. Plus, Time Machine uses non conventional folder hard links, which makes it harder to recover information. Jun 25, 2018 at 8:40

In geneal, yes, everything that is important to most users is included in a Time Machine backup. As stated in other answers, there are a number of restrictions regarding OS bootability and excluded system files and the likes, and there are certain computer-bound features like software activation of for example Adobe software that doesn’t transfer with a backup.

In most cases, you can simply buy a replacement Mac, connect the drive, and restore al the files you like, or the complete system from a Time Machine backup. Time Machine is well-documented in macOS help and on Apple’s website for more in-depth (and ever changing) information.


For maximum security, I recommend using Apple Disk Utility to make periodic bootable clones. Once my wife's Mac laptop was stolen. She could immediately boot my MacPro from her laptop's clone and be back in business. A week later she could buy a replacement laptop and clone the clone to it. Does Time Machine offer such certain salvation?

Apple Disk Utility's cloning function is rock solid, with automatic verification. Its only limitation is that the clone volume can't be smaller than the original volume (and then to go back it can't be larger). Possibly Apple Disk Utility got a bad name for cloning when, between OSX 10.10 and OSX 10.12, its GUI changed. Before, choosing a volume and pressing "Restore" set that volume as the source volume. After, choosing a volume and pressing "Restore" set that volume as the destination volume. Someone used to the earlier GUI could make a huge mistake of wiping what he wants to save. But pull yourself together and enjoy the reliable Apple Disk Utility for perfect cloning. Time Machine takes too long, and you never quite know what it's done, or will do when you're in trouble.

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