How to centralize your Time Machine backups

TimeMachineIconXTime Machine in OS X offers a quick way to back up your entire system, but one requirement for this is you need to plug in your backup drive in order to keep the system backed up. For desktop systems this is a matter of simply keeping the drive attached and tucked away behind your iMac, Mac Mini, or Mac Pro; however, if you are a MacBook owner, then you might find yourself periodically misplacing your drive, or not having it with you, and then getting messages that you haven’t backed up in a number of days. There are two easy approaches to help prevent this, especially if you have multiple Macs available.

1. Use a Time Capsule or supported NAS

The easiest solution is to purchase a Time Capsule, or a third-party device that will provide Time Machine backup services over your local network. These are relatively easy to set up, and you should then be able to locate them as a potential backup destination in the Time Machine system preferences. The caveat here is that these devices can be relatively expensive options, and may be entirely unneeded if you have a spare Mac (or even one you use regularly but which you have set up in a specific location).

2. Create your own Time Machine server

If you have only portable Macs that you move around all the time, then your best bet for centralizing backups is to use a Time Capsule or similar device. However, people with laptops may also have a desktop system available, or even an old laptop, and these can be used with your backup drives for creating a custom centralized Time Machine backup destination.

One approach for this is to share a folder from this computer, and then modify OS X on all of your laptops and other systems to show unsupported volumes as potential Time Machine destinations; however, this is unsupported and may result in odd behaviors with your Time Machine backups. In addition, it is entirely unnecessary given that for $20 you can install Apple’s OS X Server package (available here), which simply enables a number of network services on a given system, one of which is a Time Machine backup service. With this service, your Mac will in essence turn into a Time Capsule.

  1. Set up your server Mac on your network.
  2. Update it to the latest version of OS X (purchase it for free from the App Store, if needed).
  3. Purchase OS X Server from the App Store.

Note that even if your Mac cannot support the latest version of OS X, if you can access the App Store then you should be able to install a version of the Server package that is appropriate for your OS X installation, and then be able to configure Time Machine backups.

  1. Open the Server app and choose the option to set up OS X Server on the current system.
  2. Follow the on-screen instructions, and wait for the process to complete.
  3. Select “Time Machine” in the services list on the sidebar.
  4. Click the plus button and choose a folder on a local drive as the destination for your backups.
  5. Optionally limit the size of the backups for each user, if applicable.


Time Machine service in OS X

Setting up the Time Machine service in OS X will allow you to centralize backups for all systems on your local network.

At this point your server is set up. If you need more space, you can attach new drives, partition and format them, and then then similarly set up shared folders on them for different computers on your network, but this expansion can happen at your own pace and does not need to be done right away. Now you can assign your other systems to use this server in the Time Machine system preferences:

  1. Open the Time Machine system preferences.
  2. Click Add or Remove Backup Disk.
  3. Choose your server’s shared folder name from the Available Disks section.
  4. Optionally encrypt the backups, and then click Use Disk.
Time Machine preferences showing server share

The shared “Backups” destination on the server can be used as a backup destination for any Mac on your network, though perhaps consider setting up quotas and even separate shared folders for individual Macs, to better manage your backups.

There are a few things to keep in mind when using networked backups. First is that being network backups means the initial backup may take a long time to complete, up to several days; however, once done, the incremental backups should occur automatically every hour whenever you are on the same network as your server.

In addition, because of the relative slow access, network backups are best for preserving a history of your files and not necessarily great for restoring an entire system. While this can be done it may take a long time, so its therefore still good to maintain a system clone or other local backup, especially before updating or upgrading software on your system.

Also note that while this service will provide backups to the entire network, it will not back up the server itself. Consider using a dedicated partition or drive device for backing up your server.

9 thoughts on “How to centralize your Time Machine backups

  1. B. Jefferson Le Blanc

    An old Mac Pro would be ideal for this solution. You can easily upgrade the internal storage with as many as four high capacity drives.

  2. Mike Noonan

    Since TimeMachine chugs along creating a infinite timeline of archived files, besides the physical limit of disk space, how does one throttle the use of said space by multiple OS X systems as they compete for that space especially when a smaller, much more active system gets a disproportionate piece of it. Partitioning a dedicated space for each OS X system would be one method. Any others?

  3. Steve L'Heureux

    Honestly, I think putting all your eggs in one basket, so to speak, is asking for trouble. I’ve been consulting on Macs for 26 years and the solution I go to first is a dedicated clone for each machine, via Carbon Copy Cloner. Go beyond that if you like with Time Machine, Off-site and cloud backups, but get that clone done first and have it run automatically every night. You’ll thank yourself later 🙂

    1. Topher Kessler Post author

      Where your eggs lay in this instance depends on how you have everything set up. I described using one external drive attached to the server for your backups, but you can easily attach dedicated drives for each system that you use, and then set them up as Time Machine shares. In this case you will have them on different physical media, and not all collected in one location. The only common feature will be the way they are accessed–through the Time Machine service, but each will be just as separate as if you had attached the drive to the system itself.

      1. Steve L'Heureux

        Of course. Still can’t boot from a Time Machine Volume though like you can with a clone, plus CCC gives you an archive of deleted and changed files. Heck, if a person can afford it, do both!

        1. Topher Kessler Post author

          Oh I agree. I’d in fact suggest folks double-up on as many backup routines as possible, such as using this server-based setup for hourly backups of most systems. In addition, having a local drive serve as a clone, and perhaps even another serve as a TM backup will ensure not only data redundancy but also protect against device failure. If possible, having the server backups on a RAID 5/6 or proprietary but similar technology like a Drobo. I don’t think there’s much need for an internal TM backup, as TM already provides local document backups, but even that is a possibility for some folks with older tower Mac Pros.

  4. MaX

    Best backup strategy: monthly incremental Time Machine full backups coupled with daily mirror ones of newer personal data (or whatever desired) on SDXC card with application allowing it like Tri-Backup Pro.

  5. Gary Dauphin

    “Create your own Time Machine server” — I am pretty sure using the Sharing -> File Sharing system preference will work, without having to install the server software. While I am not opposed to setting up a server, this is simple enough for most home users to manage without getting into server.

    Also, if you have two or more Macs on your home network, you can turn it on on both and they can use each other as a Time Machine backup server.

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