Version 3: Use Time Machine with Windows Home Server

I have continued to work with people on getting Time Machine setup and working with your Windows Home Server. I’m calling these new directions version 3 and it’s easier than the last steps that required an applescript. The reason why the applescript wasn’t working in version 2 is that some people had a Windows partition on their Macs, including myself on my new iMac. Instead of fixing the applescript to check for multiple partitions it is easier to just use Disk Utility. Below are the new directions. I have had multiple people confirm that they are working. For informational purpose you can find Version 1 and Version 2 of my directions. Version 2 has some good comments if you have trouble.

You still need have iTimeMachine enabled.

UPDATE: iTimeMachine is no longer active. Use the following command in terminal to enable network disks. The following command does what iTimeMachine did.

defaults write TMShowUnsupportedNetworkVolumes 1

1. Open Disk Utility in the Utilities folder.

2. Select the Macintosh HD, then go to “File” -> “New” -> “Blank Disk Image”.

3. A box will come up with a lot of different options. The save as name is important as Time Machine will use that name to see if it’s correct. The save as name should be machinename_macaddress. For example mine is jeremy-iMac_0a0a0a0a0a0a. I’m not giving my MAC address but that’s what the 0a stuff is. You can find the name by going to sharing in system preferences or types hostname -fs in the terminal. The MAC address is for the connection that will be used for Time Machine. My laptops are wireless, my desktop using ethernet. Important: You need to use the MAC address for the ethernet card. You can still use wireless after is it setup and running.

4. Name = whatever you want. I called mine Time Machine.

5. Size = Over your total data amount. Right now I set mine at 400g. With Disk Utility you can resize this later if you fill the amount.

6. Partition = Single Partition – Apple Partition Map

7. Image Format = sparse bundle disk image

8. Now create the image. Default is to save to your desktop.

9. Transfer that disk image from your desktop to you time machine folder on the WHS.

10. Point time machine to your WHS folder and start the backup.

If you have questions please leave comments. As always I will try to respond as fast as I can. This is still not supported and I give no guarantee on the safety of your data or reliability of your backups. It works for me and I have been backing my Macs up to Windows Home Server for months.

If you enjoyed this post, please consider to leave a comment or subscribe to the feed and get future articles delivered to your feed reader.


As always, Thank you.

[…] You can read it here. […]

[…] Info: | Source: […]

When I follow these instructions I still get an error message saying “The Backup Disk Image ________ could not be created (error 45).”

I noticed on your Version 2 post someone mentioned using the MAC address for their Ethernet connection as opposed to their WiFi connection. When I used the Ethernet MAC address it worked like a charm.

Thank you for the instructions. You rock!

Can anyone comment on how safe this is? I noticed on the Itimemachine backup site it says use at own risk and that it still has bugs working over a network connection.

If there is one thing that I get paranoid over it is my backup data. Backing up to WHS would be ideal but I’m not sure how much I trust it.



This isn’t supported by Microsoft or Apple. So those two companies would say it’s not safe at all. If they could come up with a perfect solution they would probably provide one for us. Even the HP MediaSmart servers have had issues with reliability with Mac backups.

I have been working with this for over two years and I haven’t lost any files. Reliability on the other hand, has been somewhat iffy at times. Generally if my Time Machine backup runs into issues I take the sparse image file, move it to another folder and create a new one. That means I still have all my files. Yeah it’s a pain to create a new sparse image file but I at least know that every hour my files are getting backed up without me having to do anything. If it fails again months down the road it provides me a error message and I can recreate.

The comment on using ethernet MAC instead of wireless MAC worked for me too. Should be in the main instructions?

Thanks for this – really brilliant help….

The tutorial works but when I make my fisk image Disk utility shrink it to like 2-3 gig’s – even though I set it at 700 gigs
why does Disk utility shrink my disk image?
then when the backup on WHS starts it goes well till the disk is full then it closes

any thoughts?

A second comment
on mac pro I have had to use case sensitive – the mac told me to do it

on the mac book pro – just journaled

but both continue to fail at the 3 gig mark

OK Problem solved – of the above 2 issues
I could not get this to work on VAIl
Once I went back to whs it worked nice
THE ISSUE IN VAIL WAS THAT NO MATTER WHAT I set the sparse bundle on it only registered about 2.5 gigs in Time Machine
– so when i went to time machine once the 2.5 or 2.6 was full it shut off

MAYBE THERE IS A FIX Jeremy could come up with so that when the sparse bundle was made it registered the large backup size

I couldn’t get this to work (Time Machine kept failing to connect to the backup disk). Using the Ethernet (en0) versus wireless (en1) MAC address when creating the image fixed things for me as well – I agree this would make sense to include in the main instructions. Thanks all!


Sorry, but what does transfer the image mean exactly? How does time machine see this? Do you delete the image file on your desktop?

I really appreciate the time and effort, please make it a little simpler for us slow people.


When I try to copy the created disk image (Joshuas-MPB_a0a0a0a0a0) to my WHS home server is prompts for a password. When I enter my password it says that I don’t have permission to read them. I am the admin on the computer and I verified that the image is set to read/write for my user account. Have any advice?


NM I had to change the permissions for the folder on the WHS.

Thanks for the guide! I was able to get TimeMachine up an running without too many problems. I did identify a few minor issues that would help others. Here are the details:

If the machine name has spaces in it, so should the disk image name. Don’t replace spaces with dashes.

The MAC address to use in the file name is the Ethernet MAC address, not the wireless MAC address.

The default location of the disk image is not the desktop, it’s the documents folder. Unmount the disk image that shows up on the desktop before copying it from the Documents folder.

Creating a disk image that is 80GB (for example) will not result in an image file that is 80GB to begin with. 80GB is the maximum size, and it will expand in size as backups occur. So don’t worry about the initial image being too big to fit on your existing hard drive.

Hope this helps others with these already great instructions.

After countless attempts, I finally got this working!

Not sure which variations or details were key, but my Intel iMac machine name was lowercase, the ethernet MAC (not wireless MAC) was all uppercase, like “imac_0A2B3C4C5E6F.sparsebundle”.

I set the size to 500 GB, the type was “Mac OS Extended (Case-sensitive, Journaled)” ejected the disk image, and moved the sparsebundle file to a folder called “Time Machine” on the WHS box. Permissions were already okay when I created the folder.

iMac was connected via wireless through a router to an ASUS TS Mini, and iTimeMachine was running, selected the Time Machine folder and this time, it just worked.

Excellent guide, glad I didn’t give up on it. Hope some of the above detail helps someone with a set-up similar to mine.

[…] Version 3: Use Time Machine with Windows Home Server (tags: whs mac backup osx windowshomeserver windows timemachine) […]

“The MAC address is for the connection that will be used for Time Machine.”

Does this mean that you need a different Sparse Bundle depending on which outbound interface you use to connect to the share? Most people suggest doing the first backup via Ethernet and only then doing subsequent backups via WiFi.

Great guide.

Is there anything you need to watch out for when doing a restore? People who have done this hack for AirPort Express with a USB AirDisk suggest that you need to attach the disk locally during a restore.


Use the Ethernet MAC address. After you create it with that you can use either ethernet or wireless.

Restore: The time machine volume can’t be seen by a default snow leopard install. You will need to enable AirDisks by running the app or doing the command line. Once your fresh install can see the Time machine backup you can run migration assistant.

Thanks Jeremy.

I purchased a WD MyWorldBook Ethernet NAS, which supports time machine straight out of the box, without command line hack. Not sure whether it actually supports AFP 3.2+/3.3 or whether it pretends to support these protocols, but Time Machine seemed happy. Found an interesting article about the requirements for ‘supported’ Time Machine compatibility.

I chose the Ethernet NAS because it had a 3 year warranty compared to Time Capsule.

I hope it will do the job!

Jeremy – do you know of anyone getting this to work on an Acer H340 WHS? I can’t seem to get it to work from a MacBook Pro bought this month. I’ve created a disk image with both ‘No Partition’ (this article,, seemed to say do that) and with your suggestion of Apple Partition. However, after copying the disk image out to the Time Machine mounted drive. When I tell TM to back up, it always attempts to make a new sparse bundle package in my Time Machine share on WHS (usually with format of [Computer Name].1.tmp.sparsebundle (note the missing MAC address…I’ve tried creating bundles with and without MAC address).

If I try to make a [Computer Name].1.sparsebundle instead (kind of as how the above article mentions), then TM automatically creates a [Computer Name].tmp.sparsebundle.

In any case, TM always fails in the initial step ‘Making disk available’ (I think the message was).

In any case, I’m kind of at a loss and hoping for some insight.

Additionally, I didn’t do your instructions 1 or 2…I just followed this page, however, I did run the terminal command mentioned in the above article to enable TM to see ‘unsupported network drives’ or something.

Thanks in advance.


It has to have the MAC address in there. And it has to be the ethernet MAC address and not the wireless. I need to update the original steps to say that. Also the computer name has to be exact. I’m guessing you weren’t using the ethernet MAC address. Let me know.

I have a macbook air, it has no ethernet adapter. Which mac address do I use? It does not seem to work with the wifi mac address?

[…] [2] (No Ratings Yet)  Loading […]

This is brilliant and has helped me to start backing my Mac and MacBook Pro to my WHS.

The only comments I have are around the MAC Address and the ‘-‘ instead of a space.

I noticed that in Finder if TimeMachine creates a Temp Sparse Bundle (in the same folder where you copied the sparse bundle you created using the above instructions) then you know it’s going to fail, but this isn’t bad news, as you can then work out whether to use ‘-‘ or spaces in your computername.

You also need to check which MAC address you are using, as mine didn’t work when using the router MAC address. To find the correct MAC address click on the Apple logo in the top left, then choose more info (you should then be in System Profiler). Within System Profiler, goto Network, then locations, within here, you should then locate your Hardware MAC Address under the Ethernet section.

Hope this helps?

I keep getting Error Code 513. What am I doing wrong?

Excellent hint about seeing what ‘temporary’ file the Mac puts in the WHS folder. It was only through this, after hours of hair-tearing, I realised what I was doing wrong. My g/fs Mac is called Nicola’s Computer. With the Mac, the apostrophe was converted to the correct printers type, rather than the ‘feet and inches’ type you get from a keyboard. And again, the Mac seems to internally call itself ‘nicolas-computer’ if you use System Profiler – you need to ignore this!! Otherwise, here we go…

Did anyone find a solution for a Macbook Air (no ethernet, only wlan) yet? I take it, it won’t help if I temporarily plug in the ethernet adapter – if the adapter won’t be available later for the backup via wlan, right? Something else: the link for iTimemachine seems to be broken – I couldn’t find the download anymore.


If you plug in the ethernet adapter and build the first backup it should work over wireless after that. On my MBPs I set it up with ethernet originally and only use wireless for back up now.

Thanks for the setup step =)
I got it to work with my MBA, somewhat.
I have set the image format size to 100 GB initially.
However once time machine start, the max size change from 100 GB to 1 TB(which is max size of the WHS). I have try to re-size it down to 100 GB in disk utility, but it always go back to 1 TB.

Thanks a lot, it works !


Thanks for the write-up! I got this setup and working great for a couple of weeks…It was backing up over wireless and everything. Today I plugged back into Ethernet and I’m getting “Time Machine Error: Error Code: 13”. Any suggestions?

I had a tough time making this work. It was some kind of permissions issue on the WHS. I kept getting error 13.

I ended up putting the disk image in the Public Folder of the WHS and it finally worked. Not the ideal solution, but at least I’m backing up now.

It is crucial that you name your image file correctly, otherwise you are going to waste a lot of time trying to get it work, e g in my case the mac address of an ethernet card didn’t work, as my computer uses WINS for some reason.

The solution below worked on my PowerBook G4 with OS X 10.5.8 and I was able to back-up my computer. It took over 4 hours for as little as 24GB of data though.

1. run Disk Utility
2. hit Alt+Cmd+N
3. navigate to the folder on WHS in witch you wish to keep your Time Machine Image Drive stored. Keep the window with the content of that folder visible.
4. now go to the Time Machine Preferences
5. press ‘change disk’ and choose the desired disk on WHS (the same that you have open in Disk Utility)
6. confirm changes
7. now the Time Machine will attempt to create an Image Drive for backups.
8. you should see the file name appearing in the Disk Utility’s window, write that name down. wait for TIme Machine to finish
9. follow the steps from the tutorial on top of that page — just replace the ‘save as’ name from the step 3. with the name you have written down.

Good luck!


Your Version 3 procedure worked nicely for me till the last OS 10.6 update to 10.6.8.

Backups to the shared folder on WHS stopped working.

At first I thought the sparseimage I created to begin with might have run out of capacity. I did the process again and noticed if I created a sparseimage on the desktop, it wouldn’t copy into a mounted server folder.

I tried copying the image onto a big thumb drive and copied THAT into the WHS server volume.

The image is in the folder. If I mount the folder on the mac’s desktop and double click on the image, a volume titled “Time Machine” mounts on the desktop.

But still Time Machine can’t mount the image. This is the error message I get every time:

The backup disk image “/Volumes/Time_Capsule-2/MacBook.sparsebundle” could not be created (error 45).

Any insights you may have that lead to getting this trick working again would be greatly appreciated.

Thank for your consideration.

Bob Blomeyer

I got most everything to work using “lower case computer_UPPERMAC”, but my hard drive is only 250GB and I already have 130GB of data on it so I can’t create an image bigger than 120GB and then when Time Machine goes to back it up, it says the drive size is too small. Not really sure how to get around this one, but I’d love to hear ideas.

Have just upgraded to Lion, it seems to have made undesirable changes. Not sure if you have upgraded yet and experienced the AFP error?
Any suggestions?

I upgraded as well and unfortunately your process no longer works. Let us know if you find a work around as I’ve been unsuccessful. Thanks.

Also have AFP error on Lion, anybody found solution?

What I am wanting to know, is there a way to backup my mac to a specified Backup drive in my WHS as I do not want to back it up on the main physical drives.

I have tried to access the backup drive from inside the Mac OS X Environment but am unable to. Any input would be gratefully appreciated.

I tried this on my HP Media Smart server after having troubles with fault 45. It didnt work. I eventually called HP Support and we solved all problems by going into Home server console – accessing shared folders – deleting the entire mac-folder – adding a new folder namned mac – and then do the normal setup through HP Media smartserver preferences and time machine setting (choosing back up disk: Back up to HP Media Smartserver.

Leave a comment