Free Up Space by Moving Your iPhone and iPad Backups

Yesterday, I was attempting to update the firmware on my iPhone and iPad but was running into an error, specifically:

“iTunes could not back up the iPhone “Boyd’s iPhone” because the backup could not be saved on the computer.”

This was due to the C: in my computer reaching its capacity. Using a 128GB solid state drive meant I had to come to a decision about how to carve it up for the operating system and applications. I wanted to give enough space for applications so I split the drive roughly as follows:

  • 40GB operating system partition (C:),
  • 80GB application partition (D:).

The C: was always going to be a bit of a squeeze and I usually ran within about 2 or 3GB of maximum capacity. Things have been running fine for ages until yesterday. iTunes seemed to consume quite a bit of space in “C:\Users\<Username>\AppData\Roaming\Apple Computer\MobileSync” during the upgrade process and, in doing so, used up every last megabyte of space on the operating system partition.

Meanwhile, I had a 1TB hard drive as a data partition (E:) with some 830GB free. I thought to myself that surely there was a way I could move my iPhone and iPad backup to the E: as well as the temporary scratch pad used by iTunes during its upgrade.

I was right.

Without getting too technical, the default file system on modern Windows computers (which is NTFS – or New Technology File System) allows for something known as a “symbolic link”. A crude summary of this functionality is that you can repoint a folder (or file) that seems to exist in one location to another one in a completely different location.

So how did I do it?

Despite Windows 7 including a command line tool “mklink”, I used something called “Junction” created by Windows Sysinternals in 2007 and available here. It’s fairly straightforward to use too. Before I used it though, I renamed my existing backup folder @ “C:\Users\<Username>\AppData\Roaming\Apple Computer\MobileSync\Backup” by putting a “1” on the end and copied its contents across to a folder on the data partition.

Then, I opened an administrative command line and typed in the following:

  • junction “C:\Users\<Username>\AppData\Roaming\Apple Computer\MobileSync\Backup” “E:\Backup\iTunes Backups”

Once I confirmed the iTunes wasn’t upset with using a directory symbolic link, I deleted the backups (and temporary files as a result of the failed firmware update) on the C: which raised my free space back up to 7GB.

Problem solved. As an aside, I have also found that iTunes is significantly faster as a result of enacting the above.

I’m sure there are other applications for the use of directory symbolic links but I thought this was a useful scenario in which others might find themselves.

4 comments

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    • oliver on November 2, 2010 at 20:32
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    Great stuff! Any way to do this on a mac?

    1. Yes, this can be done on MacOS X – if you want an idea of how it is done check out the link @ http://hints.macworld.com/article.php?story=2001110610290643

  1. Hi Boyd,

    Thanks for the post, it helped me.

    Mayby you can make two adaptions in de tekst. First switch target and original directory. Second mention that you have to have admin rights and must open the command prompt as admin.

    Thanks!
    Ole

    1. Hi Ole,

      Thanks for the feedback and you’re right! I had used the syntax for MKLINK which has the link before the target as opposed to junction that has the target before the link. I have now fixed it up.

      Boydo

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