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The vast majority of Windows applications park their backups and bulky data directories right on the primary partition. This means the precious space on your Solid State Drive (SSD) is chewed up by backups, a less than ideal situation. Read on as we show you how to move your backups to a data disk.

Why Do I Want to Do This?

Most people have switched to using a speedy Solid State Drive (SSD) as their primary drive. These drives are known for their snappy response time, not their expansive storage capabilities. There's no sense in storing bulky and infrequently accessed data like your iPhone and iPad backup files on your SSD.

Furthermore, in some instances, application functions will outright fail if the primary disk doesn't have enough space. Modern iPhones and iPads all have internal storage measured in hundreds of gigabytes. A few complete backups can put a serious dent in your average SSD. Even though SSDs are getting larger and less expensive, as of August 2022, they still cost more per gigabyte of storage than conventional hard disk drives, making hard disk drives extremely appealing for storage-heavy uses.

Related: CMR vs. SMR Hard Drives: What's the Difference?

In today's tutorial we're going to look at a quick and painless way for Windows users to easily move their backup and/or data directories for iTunes (or any other Windows application that doesn't support in-app backup/data directory changes) to a secondary disk.

What Do I Need?

You need precious little for this tutorial. The tools for adjusting the location of the directories within Windows are built right into Windows.

Beyond that, the only thing you'll need is a secondary drive to move the backup data to. For this tutorial, we'll be moving our backup data to the F:\ drive, but any large disk that isn't your operating system disk will do.

Finally, although we'll be specifically moving the iTunes backup directory to our secondary disk, you can use this trick to move any bulky data or backup directory off your small primary disk onto a larger secondary disk --- you'll just need to locate the data directory on your primary disk and adjust the commands accordingly.

The magic that drives this entire operation is the symbolic links system. A symbolic link is effectively a very advanced shortcut that is transparent to the requesting application. After we move the iTunes backup directory, iTunes will never be the wiser (but the iTunes data will end up on the secondary disk). If you would like to read more about symbolic links, check out our Complete Guide to Symbolic Links (symlinks) on Windows or Linux. Otherwise, let's dig in.

Create a New Backup Directory

Before we point an application at a new backup directory, we need a new backup directory. As we noted above, we're going to redirect iTunes to the F:\ drive. In light of that, we've created a new folder "iTunes Backup" on the F:\ drive. Create a new backup folder on your secondary drive now.

File Explorer open to the new iTunes Backup folder on the F:\ drive.

Locate and Rename the Current Backup Directory

We need to locate the current iTunes backup directory and rename it.

Press the Start button, then paste the following in the search box:

"%APPDATA%\Apple Computer\MobileSync"

This will take you to the backup folder used by iTunes. Within that folder you will see a folder simply titled "Backup". Rename that folder "Backup-Old".

The original backup folder has been renamed "Backup-old."

Open a Command Prompt

Hold down the Shift key and right click inside the File Explorer pane of the current folder (/MobileSync/). Select "Open Command Window Here" to conveniently open a Command Prompt already focused on the current directory. Alternatively, you can type "cmd" into the File Explorer address bar and hit Enter.

Command Prompt open to the new backup folder, with the symbolic link command pasted in.

Any file path that contains a space must be in quotation marks. For example, C:\FolderName doesn't require them, because FolderName is one word. If it were named Folder Name, then the path would be written C:\"Folder Name" or "C:\Folder Name" instead.

At the command prompt, again ensuring you're in the MobileSync directory, enter the following command (adjust the F:\iTunes Backup entry to point at your chosen backup directory):

mklink /J "%APPDATA%\Apple Computer\MobileSync\Backup" "F:\iTunes Backup"

The "mklink" command is the Windows shell command for creating a symbolic link and the "/J" switch creates a special type of symbolic link known as a Directory Junction, which will seamlessly redirect any applications that query the original Backup directory to the iTunes Backup on the secondary disk.

Command Prompt open over File Explorer, showing the symbolic link command and the link it created.

At this point you should see a folder with a shortcut icon in the \Mobile Sync\ folder, labeled Backup. If you click on this folder it will appear to open like a normal folder (you will not appear to switch over to the secondary drive like you would with a regular shortcut) but anything placed in this drive will be physically stored on the secondary disk.

Test the Junction

If you can click on the link without an error, everything should be good to go, but we're going to double check it to be safe. While in the \MobileSync\Backup directory (accessed via the new symbolic link you just created) right click and create a new text document as a temporary file place holder. After creating it, navigate to the actual backup directory you created on the secondary disk (in our case, F:\iTunes Backup\). You should see the file sitting in the directory. Delete the place holder file once you've confirmed that it is in the secondary directory.

Initiate an iTunes Backup

Whether you're following along with this tutorial to transfer the iTunes backup directory or the backup directory of another Windows application, the real test is whether or not the application works as intended with the symbolic link in place. Let's fire it up and see.

After initiating the backup process, visit the backup directory on the secondary disk:

A new backup successfully moved data to the F:\ drive.

There we can see a brand new collection of backup files created at the time of our new backup. Success!

Copy the Original Backup Data

In the beginning of the tutorial we renamed the Backup directory to Backup-Old. That Backup-Old directory contains all your old iTunes backup files. Now that we've successfully tested the symbolic link and performed a successful backup operation, it's time to move the backup data to its new home.

Unlike a regular same disk-to-same disk transfer, this transfer will take a little longer as Windows copies the data through the symbolic link to the secondary disk. Once it has completed the copy you can again confirm that the data is safe on the secondary disk.

Left Properties window shows C:\ storage usage before moving backups to the symbolic link. Right Properties window shows the C:\ drive after moving the files.
Left Properties window shows C:\ storage usage before moving backups to the symbolic link. Right Properties window shows the C:\ drive after moving the files.

As you can see in the screenshot above, after we copied the iTunes backup directory, we freed up around 7 GB of data on our primary disk. The entire process took around 5 minutes from start to finish and our reward is extra space on our primary disk,  and backup data stored on a secondary disk.