How to Use Time Machine Server in macOS High Sierra

Some Mac users have long run Mac OS X Server on a computer in their household to use as a file sharing repository, and to centralized backups of other Macs. The Server software had a Time Machine server feature, which allowed you to designate a folder that other Macs could select to store Time Machine backups. This is especially useful if you have laptops that you don’t often connect to hard drives to back up; Time Machine can do this automatically, in the background, even at night.

With macOS High Sierra, this feature is built into the operating system, and you no longer need to install and manage Server to use it. Here’s how.

Choose a folder on your Mac for backups. Go to System Preferences > Sharing, then check File Sharing to activate it. In the Shared Folders section, click the + button, then choose the folder you want to use for your backups.

Right-click that folder in the Shared Folders list and choose Advanced Options. Check Share as a Time Machine backup destination.

Time machine server

On the Mac you want to back up, mount the shared folder, then open the Time Machine pane of System Preferences. Click Select Disk, and choose that folder. That computer will shortly begin backing up to that remote folder. Note that you can limit how much storage will be used for backups in this dialog; if you don’t, I assume that all available space will be used, which could be a problem.

With a laptop, macOS keeps local snapshots that it stores every hour, so if you’re not connected to your network, it won’t back these up, but will do so some time after you’ve rejoined the network (when the next Time Machine backup runs).

Thanks to this new feature in macOS High Sierra, many people who set up a Mac using Server can now eschew this additional layer of software. This makes things a bit easier for those who don’t need the advanced features of a server.

29 thoughts on “How to Use Time Machine Server in macOS High Sierra

  1. You don’t need to mount the shared folder on the Mac you want to back up. It will show up automatically in the list of available destinations in the Time Machine preference pane.

    • That wasn’t the case for me. Also, the Time Machine icon doesn’t display consistently when a folder is shared.

  2. Really? Man, I can’t even get Time Machine to function correctly on my external drives!! Then, I wiped the drive clean and it still didn’t work!!

  3. External USB drives always complain that they were disconnected after I wake my iMac from sleep so the only way I could use Time Machine, or any other automatic backup software, would be to leave my computer running 24/7. That’s a ridiculous waste of electricity so I’m stuck with periodic manual backups on a drive I mount to complete the backup and then unmount and turn off so it doesn’t get corrupted. You’d think Apple would have figured out how to deal with external drives by now.

  4. Ehh… This is not working for me. I’ve tried this multiple times. I can connect to the shared folder on the Mac I want to backup to TM but I never see it in TM as a connected drive. I wonder if it’s because it’s an external connected drive that I’m having this issue.

    I’ve had nothing but issues with TM for years. Once I get it set up, it works but if anything ever bobbles, I have to dig and dig and dig for answers.

    I think after this latest iteration of change, I’m done with TM.

  5. I am having no luck at all with several Macs with older versions of OS X, specifically Snow Leopard and Mountain Lion. Even Yosemite and El Capitan cannot see it.

    But High Sierra can connect successfully to Mountain Lion Server Time Machine server.

    I guess I am sticking to an old version of Server instead of High Sierra.

    Backwards compatibility? Not from Apple it seems.

    • After having tried several times mounting the shared folder on the target machine with Time Machine not able to see it, I restarted the “server”, mounted the shared folder, and now I can see it.

      Nothing like consistency :-(

  6. You have the setup, but not the management.

    Setup is easy but what if I want to delete older backups? I could check the box that says to delete older backups when the space is full but it doesn’t do it for shared time machine drives.

    In Server I could easily manage Time Machines and delete them out right in the interface. Now the only way I can see is to go in the drive an manually delete it in Finder but all I have is a huge .sparsebundle file for each user. I can’t delete individual backups at all when I need to.

    If they would have included the management in settings I would be fine with cutting it out of but they didn’t. It’s just missing.

    What’s your solution?


  7. Yeah, removing any management is a deal-killer for me. I’ve got an office with about 30 Macs that back up to a central Time Machine server. Sometimes, for whatever reason, a machine hasn’t backed up in a while. I can see that instantly on the server, and the server will email me when someone hasn’t backed up in a few days. It seems with this arrangement in High Sierra, all that is gone?

  8. Awesome article, thank you for solving the time machine element for me (it’s gone from services in Mac OS Server now).

  9. The “awesome article” was so awesome that I am overwhelmed by its awesomeness – I don’t understand even a particle of it.

    I use to love Time Machine since I became a Maccer at Snow Leopard, and used it to bail myself out of problems occasionally.

    Then it snafu’d and wasn’t working properly when I got into REAL problems – desktop and iPhone decided to backup at the same time and both were mangled forever. Time Machine was useless.

    Now I don’t even know if Time Machine is working and if I need it sometime in the future I don’t know where / what / how to run it.

    • “desktop and iPhone decided to backup at the same time and both were mangled forever”

      Time Machine doesn’t have anything to do with iPhone backups, just for the record.

      • Time Machine does back up iPhone backups, however. I’m not sure exactly what is meant by “mangled,” but perhaps something happened because iTunes was writing files to an iTunes backup while Time Machine was copying files.

  10. I was able to create the folder and see it from the computer I was about to back up. However, even though I know the password and user name I can not connect to it

  11. You’ve been able to backup to shared network folders with Time Machine for years. How is this really any different? Thanks.

    • You have been, but it was not supported and was a bit of a fudge. So do you really want your backups depending on an unsupported hack?

  12. I was referring to regular Mac OS. I wonder what this does that is different from backing up to a shared network folder on previous versions of Mac OS?

    • Backing up to a shared network folder was possible but kind of a hack. With OS X Server it was a built-in, documented, supported feature. Until it was subsequently yanked in High Sierra and put into the regular OS. With zero documentation or configuration, etc.

      Basically if you depend on the Mac for ANY kind of server stuff, start looking for replacements. It is abundantly clear that Apple is ditching any and all server-side stuff from the Mac.

  13. There’s one step missing from this post, at least in my experience. After adding and configuring all the folders, it’s necessary to turn File Sharing off and back on. (In my case, I was getting errors from my Time Machine clients before I did this. In other circumstances, it might be impossible to get the clients to connect at all without doing this.)

    The checkbox in the Sharing preference pane will suffice for turning it off. However, clicking that checkbox again will only turn on SMB, not AFP. If you want to turn both SMB and AFP on (for instance, if you still have some Macs running El Capitan or earlier), use the Options button to turn File Sharing back on, rather than the checkbox.

  14. Do you have to create a new backup folder location for each mac time machine backup you need, or can you backup up multiple mac systems to one folder?

    I’ve moved from the old server software and setup one folder and moved the old TM backup bundles into the folder. I was able to connect the first mac, but the second mac identified the old bundle but said it was already mounted.
    The third mac did backup but created a new sparesebundle and did not utilize the existing bundle.
    The fourth mac gave the same mount error as the second.

    I’m wondering if it will work if there are no TM backups mounted at the same time, in effect only allowing one backup at a time. Which is not optimal since the old server allowed for synchronous backups (I believe).

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