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Speed Time Machine Past 88MPH Over Your Local Network.

As far as backup strategies go, Time Machine is a pretty good addition to your backup strategy. You get hourly backups, can go back and retrieve accidentally-deleted files and can even restore your system from it. At both home and work, I use it as part of my backup strategy, filling in the spaces between regular clones of my system. In fact, the only thing I dislike about Time Machine is how long it takes to create its initial backup if you’re backing up to a shared drive over a network.

Recently, I took the opportunity to centralize the majority of my storage in my home to drives attached to an older MacBook Pro. As part of this project (which is the topic of a different article down the road), I put a 2.0TB drive in an older USB 2.0 miniStack, and wanted to use this as the Time Machine drive for my current MBP. The problem was that—regardless of whether I connected to that drive via WiFi or via Ethernet—Time Machine kept telling me that a backup of the approximately 250GB would take around a week or more to make.

Obviously, this was not acceptable.

Drawing from various sources on the Internet (where, apparently, there are a large number of people with similar complaints), I was able to paste together a solution that enabled me to get Time Machine’s initial backup time to reduce from over a week to just under two hours.

Note: I performed these steps in OS X 10.8.3; while this certainly should be possible with earlier (and I would assume later) versions of OS X, your mileage may vary.


For this method, there will be a bit of swapping of drives and computers, and if you’re not paying attention, it may get a little confusing. To help keep things straight, here are the terms I’ll use throughout the article.

  • TM Drive – This is the drive we’re going to use for our Time Machine backups.
  • Server Mac – This is the computer that—at the end of things—will have the TM Drive Connected to it. Keep in mind that once things are completed, this computer needs to always be on, as Time Machine will connect to it regularly.
  • Client Mac – this is the Mac that you want to back up over the network using Time Machine.

Step 1. – Start with a freshly-formatted Time Machine Drive.

The first part of all this is to make sure your Time Machine drive/partition is empty. At the very least, make sure there are no Time Machine backups from the Server Mac on it. I tried doing this after backing up the Server to the TM Drive first, but things got ugly quickly. If you’re going to back the Server Mac up to the same drive you’re backing up your Client Mac(s) to, you will need to set that up after you set up Time Machine on the Client Macs.

Step 2. – Share your Time Machine Drive on your Network

Attach your TM Drive to the Server Mac. Enable File Sharing on your Server Mac and add the Time Machine drive to the list of “Shared Folders” by cliking the “+” button and selecting it from the dialog box.

Step 3. – Mount the Time Machine drive via your network.

On the Client Mac, connect to the Server Mac and select the TM Drive you’re going to back up to. The drive should now appear on your desktop, similarly to as if you had it connected directly.

Step 4. – Select the networked drive in Time Machine.

Open the Time Machine preference pane on your Client Mac, make sure it’s set to “On”  and click the “Select Disk” Button. You should see the networked TM Drive as one of your choices. Select it and click the “Use for Backup” button. You will likely be asked for a username/password for an account on your Server Mac. However, if you added the drive to the “Shared Folders” list in Step 2, you should be able to simply connect as Guest with no issues.

Step 5. – Start the initial backup normally.

At this point, the backup process will begin. Time Machine will create a temporary disk image as it starts the backup process. Depending on your particular network setup, this may take a while. Once the Time Machine volume is set, the image will change to a standard Sparse Disk image with the name of your computer as its name (computername.sparesebundle) and your data will begin to transfer over.

Step 6. – Stop the initial backup.

Once data starts to transfer, you’ll see how much is going to be moved and how long it should theoretically take (usually several days, depending on how much you have to transfer). Immediately cancel the backup by clicking the little “x” next to the progress bar. The disk image Time Machine made should still remain on your external drive.

Step 7. – Attach the Time Machine Drive to the Client Mac directly.

Once the Time Machine backup has been halted, unmount the TM Drive from the Client Mac by simply dragging it to the Trash. Then, do the same on the Server Mac, where the drive is connected directly. Once it’s unmounted there, you can safely disconnect the TM drive from the Server Mac and attach the TM Drive directly to the Client Mac.

Step 8. – Complete the initial backup.

Once the TM drive is mounted on the Client Mac’s desktop, open up the Time Machine preference pane again, and reselect the TM Drive from the list. In later versions of OS X, it may appear twice; simply select the “new” listing and DO NOT use the “Remove Disk” option for the existing “Backup Disk” listing. The backup should complete a lot faster now (usually dropping from several days to just a couple of hours). Once the initial backup has completed, use the Time Machine app in the Dock or the Time Machine menu bar item to enter the Time Machine interface. You can then exit Time Machine and unmount the drive from the desktop.

Step 9. – Reestablish the Time Machine Drive as a networked drive.

You can now reattach the TM Drive to your Server Mac. Once it shows on the desktop, you can then reconnect to it with your Client Mac like you did in Step 3. Once the drive is mounted, you can then re-select it as your Time Machine drive, like you did in Step 8.

Once again, enter the Time Machine interface from either the Dock or menu bar item and then exit again.

Step 10. – Your Client Mac is now ready to back up over the network.

At this point, you can unmount your TM Drive from your desktop. Now, when it’s time for Time Machine to back up, it will automatically mount the disk image over the network, back up to it, and disconnect again.

If you have other Macs you would also like to back up over the network, simply repeat Steps 3 through 9 for each Mac you want to back up.

The more copies of your data you have, the more prepared you are in the event of drive failure. Now that we’ve sped up that initial backup, we’ve removed the most inconvenient hurdle to setting up Time Machine, we have a convenient way to back up over your local network that’s already built in to OS X.

M. Chris Stevens
the authorOWC Chris S.
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  • Step 8 is flawed… TM will erase the drive

    “The volume must be erased because it contains existing data.”

    So this trick is pretty much history these days

  • This process doesn’t really work as described when using the application that has replaced OS X Server. Any chance we could get an update? I’m sure other people are also interested.

  • Thank you for posting this. I’ve followed your steps above but still have a local backup and a wireless backup; the sparsebundle that was created wirelessly when I started and stopped the backup, and the complete backup that was created locally thru usb. When I plugged my hdd containing the time machine back up into back into my wireless network, Time Machine tried to create a new backup, which takes me back to square one – 2 weeks to create a wireless backup, not to mention having to reformat the drive again to delete the local backup. I’ve repaired permission,etc. Any other ideas as to why my Macbook won’t recognize this backup wirelessly? 2010 MBP running Yosemite.

    • I’ve seen issues like this before and they are commonly fixed by removing the Time Machine drive from the Backup Disks section and than adding it back again.

  • Funny enough I am doing the same thing that you describe here.

    My question is: While this fixes the issue of slow backups over Ethernet to an OS X Server, it does not fix the issue long term.

    When I did my initial backup from an iMac to a Mac Mini running OS X Server with a drive connected through FW800, I got around 40MB/s. But after my upgrade to Yosemite, I wanted to start a new backup and leave the old Mavericks sparse bundle untouched.
    But now the backup is suddenly below 6MB/s! Indeed, when I use the method above, I achieve 80MB/s.
    But what happens when it is ready and I connect it to the OS X Server again? Suppose I copied a 10GB video file to my system? Will it back it up with 5MB/s? That would be at least 1 hour.
    What is causing this extremely slow transfer rates when backing up over the network to an OS X Server?
    Are there methods to tune the network/OSX Server?

    • There are several factors that go into determining the speed of a backup, but doing so over a network will almost always be slower than over a direct connection between the drive and computer. Normally the slower speed isn’t too noticeable, but if you are backing up large changes or starting a new backup there is a lot of data that needs to be transferred and that will take some time. As long as you are connected over a network, you will get the slower speeds. If you need to backup a large amount of data it is best to repeat the steps in this blog for the best performance, then you can go back to backing up the small changes over the network. Alternatively, if you add a lot of data to your computer on a regular basis, it may be better to have the backup drive connected directly to the machine instead of over the network.

  • I don’t know if you still look at these comments after more than a year, but I ran into this problem when I tried to back up my MacBook Pro through my desktop.

    I set it up by following the instructions for using OS X Server to do this, as shown in this video from MacWorld:

    But I ran into this several-day backup thing… so I searched around and found this page, which looked promising.

    I followed your instructions, but when I hook the hard drive back up to the server Mac, and connect to the drive with the Client Mac — when I initiate a Time Machine backup, the backup disk image is not recognized — it is ignored and a new one is created, and I am back to step 1.

    I am hoping you have some insight — is this because I installed Mac OS X Server?

    Please help! (And… thank you!)

    • This sounds like a permissions issue. I’d recommend to run repair permissions on the client and server computers from Disk utility a few times.

      If the issue persists it is best to erase the TM drive and start over.

      • No go. IU repaired permissions three times on both machines, reboots, repaired twice again for good measure, and tried the backup. Speedy as snails.

        I just finished the initial backup. I hope the subsequent ones go much more quickly…

  • This may not belong in this conversation but it’s kind of related….

    Down at the local (other store), there’s a WI-FI drive intended to allow multiple computers connect to it over a local network. It’s 802.11n I think and 3Tb’s. We have a wi-fi printer sitting over there in the corner (no cables to it) and have found that we can print to it from any of the three computers in the house and we like that. I was thinking of getting a wi-fi enabled HDD of a significantly large capacity and partitioning it, and devoting an entire partition to each of our three computers just for Time Machine. And with it being over there in the corner, we really wouldn’t care how long it took.

    So does OWC sell any wi-fi enabled HDD’s? I’ve never seen one identified as such.

  • Good grief!

    The question: What was slowing your backup? You should have opened Console to see what the hangup was. Once a new backup threatened to take a long time – Console showed the problem to be Finale 2009 Help files – as I was then on Finale 2011, deleting those old files solved the problem.

    If initial backup is slow, here’s a trick that often works. Start your Mac in Safe Mode, shut down and re-start. Fixes many issues that slow down TM.

    Although starting with an empty drive is a good idea, the problem is that there is often a corrupt directory. Disk Warrior can repair TM drive directories and it has sped up more than one of my drives.

    • It’s unclear what’s slowing that initial backup, but based on the results of not only my main MBP’s backup, but also on my “Photo” MBP (pretty much stock, with only Aperture, Final Cut 4, Motion 4, and Photoshop CS5 installed on it) I would surmise that it has more to do with the network itself, as Aperture is the only application installed on both computers.

      If you have another method you prefer; by all means, continue to use it. The method outlined above is simple, effective and consistent, which is why it was offered as an easy solution to those without one and who may not have the skills or patience required to hunt down every file that may take longer than it should.

  • I start my full backup over wifi-n and then connect an ethernet cable directly. This speeds the process up by a factor of five. It takes a minute for the mac to realize it has a better connection available.

    • In many cases that works fairly well; it mostly depends on the network itself.

      However, in my particular situation, it didn’t improve things. Judging from the number of questions in Apple’s “Discussions” forum (as well as several other Apple-centric sites) this is frequently the case.

      This solution worked, and worked consistently with both my main MacBook Pro and with others I have on the same network. If you’re having troubles with your initial TM backup, you may want to give it a try. If you’ve got a nice, fast network and everything is transferring to your liking, then you probably don’t need this, then.

  • First of all, that huge amount of time is false. I’ve done migrations, and new TimeMachine backups many many times, and when the computer tells me it will take a week, or 87 hours or whatever, I have learned that IT LIES!!

    Migrating or backing up from and to a pair of 2 or 3 TB drives, tells me it will take an ungodly amount of time, BUT, the longest its EVER taken is just under 5 hours, on 800 Firewire.

    • I appreciate the fact that the “time remaining” given by the progress bar is approximate, at best. However, this was not my first experience with assembling such a setup. In my previous experiences, it wound up taking the better part of a weekend to back up over a network—and that’s with it wired, not via WiFi. Though not part of the article, during my initial attempt at setting TM over the network, I let it run overnight; when I checked it the next morning, the progress barely moves, it was still showing several days left.

      As far as I’m concerned, anything longer than an overnight backup is unacceptable. This process speeds up that initial backup considerably, as it allows me to direct-connect. In my case, it was via USB 2.0; Firewire 800 would have been even faster.

  • If you left the initial backup run over the network would it _really_ take a week? Are you sure that’s not just Apple’s estimator being way, way off? If so, it seems like something is wrong with your network! I have three MacBook Pro’s that all backup over Wifi (Airport Express-N) and when they need a new full backup I just let them run overnight and they are done by morning. For even faster results, plugging into my Gig ethernet network results in a speedy backup, nearly as fast as a connected USB2 hard drive.

    • As I mentioned elsewhere in the comments, I originally let my initial backup go overnight and saw little progress in the morning. This coincided with the performance shown with similar setups I had in the past.

      With anything involving a local network, many factors can come into play, including other items on the network (I have an old 10/100 NAS unit that may have slowed things down), WiFi usage in the area (my AirPort menu regularly shows over a half-dozen SSIDs from a local wireless ISP, not to mention the residential ones, so things can get a little crowded), and a host of other little factors. At work, I can nearly saturate the Gigabit Ethernet’s bandwidth when archiving things to our video server. Different setup and configurations, and therefore different performance.

      You may have optimal speeds over your network and had a super-fast initial Time Machine setup. That’s great; you don’t need this article, then. For those of us with less-than-optimal conditions, though, this methodology may speed up a process that may have been otherwise daunting.

  • OWC Chris S wrote, “Note: I performed these steps in OS X 10.8.3; while this certainly should be possible with earlier (and I would assume later) versions of OS X, your mileage may vary.”

    You will be pleased to know that this process worked and continues to work for previous OS versions with time machine. You can even create a disk image for use locally, thus allowing portable Time Machine volumes.