Your Guide to the OS X Yosemite Migration Assistant

 Apple has included a Migration Assistant application in OS X since the very early days of the OS. Originally, the app's main task was to move user data from an existing Mac to a new one. Over time, the Migration Assistant took on new tasks and added new features. It's now one of the easiest ways to migrate data between Macs, from a PC to a Mac, or even just from your old startup drive, as long as the drive can be mounted somewhere on your network.

There are other capabilities and subtleties built into the Migration Assistant; that's why we're going to take a look at how to use the OS X Yosemite Migration Assistant to move data between your Macs.

OS X Yosemite Migration Assistant: Transfer Your Data to a New Mac

Migration Assistant screenshot


Migration Assistant hasn't changed much since the OS X Mavericks version, but it has added the ability to copy a user account to a destination Mac even when the user account is already present on the destination Mac. This happens when you follow through the OS X setup utility and create an initial admin account. Most of us create the admin account on the new Mac with the same username and password we used on our previous Mac.

In pre-Yosemite versions of Migration Assistant, that worked fine until you got around to copying your user account data from one Mac to another. When you tried to do that, Migration Assistant would balk at copying the old user account because an account with the same name already existed on the destination Mac. It's perfectly logical to want to use the same account name on both Macs, but Migration Assistant refused to believe it.

The workaround was easy enough, if a tad awkward: Create a new admin account with a different username on the new Mac, log in with the new admin account, delete the admin account you created during the OS X setup process, and then run Migration Assistant, which would now gladly copy the account over from your old Mac.

OS X Yosemite's Migration Assistant can handle the duplicate account issues with ease. It gives you multiple ways to deal with the problem, all without having to stop and perform some sort of workaround.

Migration Assistant Capabilities

Data migration can be performed between two computers connected via a wired or wireless Ethernet network. You can also migrate data using a FireWire network or a Thunderbolt network. In these types of networks, you connect two Macs using either a FireWire cable or a Thunderbolt cable.

Migration can also be performed from any startup drive that can be mounted on the destination Mac. For instance, if you have an older Mac that has had hardware problems, you could install its old startup drive in an external enclosure and connect the enclosure to your new Mac via USB or Thunderbolt.

User data can also be moved from a PC to a new Mac via a network connection. Migration Assistant can't copy PC applications, but your user data, such as documents, pictures, and movies, can all be migrated from a PC to your new Mac.

Migration Assistant can transfer any user account type from the source Mac to the destination Mac.

It can also transfer applications, user data, other files and folders, and computer and network settings.

What You Need to Migrate User Account Data

This guide will show you, in detail, the steps to move your user account data from an older Mac to a new Mac connected via your home or office network. This same method, with just slight changes to button and menu names, can also be used to copy an account from a startup drive connected directly to the new Mac, or from Macs connected via FireWire or Thunderbolt cable.

  • A working Mac that contains your older user account information, and that is connected to your home or office network, or connected to your new Mac via FireWire or Thunderbolt cable.
  • Enough free space on the new Mac to hold all of the user account data you plan to copy over.

If you're ready, let's begin. 

Getting Set Up to Copy Data Between Macs

Migration Assistant Transfer Options


Using the Migration Assistant app that comes with OS X is relatively painless; the version included with OS X Yosemite contains a few improvements over previous versions to make the process even easier.

In this guide, we're going to use the Migration Assistant to copy our user and application data from an older Mac to a Mac we just recently purchased. This is the most likely reason to use the Migration Assistant, but there are other reasons to use it, including copying your user data to a clean install of OS X. The major difference between the two uses of the Migration Assistant is the source of the data. In the first case, you're likely copying files from an older Mac that's connected to your home or office network. In the second, you're probably copying files from a startup drive connected to your current Mac. Otherwise, the two methods are pretty much the same.

Let's Get Started

  1. Make sure both the old and new Macs are on and connected to your local network.
  2. On your new Mac (or the Mac on which you performed a clean install), make sure the OS is up to date by launching the Mac App Store and selecting the Updates tab. If there are any system updates available, be sure to install them before proceeding.
  3. With the Mac system up to date, let's get going.
  4. Launch Migration Assistant on both the old and new Macs. You'll find the app located in /Applications/Utilities.
  5. Migration Assistant will open and display an introduction screen. Because the Migration Assistant is used to transfer data, it's important that no other app is making use of the data that will be copied and moved around by Migration Assistant. If you have any apps open other than Migration Assistant, quit those apps now. When you're ready, click the Continue button.
  6. You'll be asked for an administrator password. Supply the information and click OK.
  7. The Migration Assistant will display options for the transfer of information between Macs. The options are:
    1.  From a Mac, Time Machine backup, or startup drive.
    2. From a Windows PC.
    3. To another Mac. 
  8. On the new Mac, select "From a Mac, Time Machine backup, or startup drive." On the old Mac, select "To another Mac."
  9. Click the Continue button on both Macs.
  10. The new Mac's Migration Assistant window will display any Macs, Time Machine backups, or startup drives that you can use as the source for the data you wish to move. Select the source (in our example, it's a Mac with the name "Mary's MacBook Pro"), and then click the Continue button.
  11. Migration Assistant will display a numeric code. Write down the code, and compare it to the code number now being displayed on your old Mac. The two codes should match. If your old Mac isn't displaying a code, it's likely that the source you selected in the previous step wasn't the correct one. Use the back arrow to return to the previous step and select the correct source.
  12. If the codes match, click the Continue button on the old Mac.

Go on to Page Three for information on how to use the list of items that can be transferred, and to complete the transfer process. 

Use OS X Yosemite Migration Assistant to Move Data Between Macs

Migration Assistant Transfer List


In the previous steps, you launched Migration Assistant on both your old and new Macs and set up the assistant to transfer files from the old Mac to the new Mac.

You verified that the two Macs are in communication by matching a code number generated by the Migration Assistant app, and you're now waiting while your new Mac begins gathering information from your old Mac about the type of data that can transfer between them. This process can take a bit of time, so be patient. Eventually, your new Mac will display a list of items that can be migrated to it.

The Transfer List

Applications: All applications installed in the Applications folder on your old Mac can be transferred over to your new Mac. If an application exists on both the old and new Macs, the newest version will be retained. You can only bring over all applications or none; you can't pick and choose apps.

User Accounts: This is likely the main reason you wanted to bring data from your old Mac to your new Mac. All of your documents, music, movies, and pictures are stored in your user account. The Migration Assistant allows you to copy or ignore each of the following user account folders:

  • Desktop
  • Documents
  • Downloads
  • Movies
  • Music
  • Pictures
  • Public
  • Other Data

The other data item is essentially any files or folders you created within your user account, but are not within any of the special folders named above.

Other Files and Folders: Files and folders refer to items that reside at the top level of the old Mac's startup drive. This is a common installation point for many UNIX/Linux applications and utilities. Selecting this option will ensure that any non-Mac apps you may have installed are also brought over to your new Mac.

Computers and Network Settings: This allows Migration Assistant to bring settings information from your old Mac to your new Mac. This includes such things as your Mac's name, and network setup and preferences.

  1. Each item will have a checkbox which lets you decide if you wish to move the associated items to your new Mac (a check mark present) or not move them (an empty checkbox). Some items with have a disclosure triangle, indicating that you can choose to move all or some of the related items. Click the disclosure triangle to see the list of items.
  2. Select the items from the transfer list that you wish to copy to your new Mac, and then click Continue.

User Account Mitigation

Migration Assistant can now resolve user account duplication problems that have been an issue in the past. With previous versions of Migration Assistant, you couldn't copy a user account to your new Mac if that user account name was already present on the new Mac.

This often happened during the OS X setup process on the new Mac, during which you were asked to create an administrator account. Like many of us, you probably picked the same account name you were using on your old Mac. When it came time to migrate data from the old Mac, Migration Assistant would throw up its hands and say that it couldn't copy the data over because the user account already existed.

Luckily for us, the Migration Assistant now provides two methods for resolving user account duplication problems. If Migration Assistant determines there will be an account duplication problem, the user account name in the transfer list will include red warning text that says:

"This user needs attention before Migrating"

  1. If you have a conflict with user accounts, the Migration Assistant will now display a drop-down pane asking you to pick one of two methods to resolve the conflict. Your choices are to:​
    1. Replace the user account currently on the new Mac with the one from the old Mac. If you select this option, you can also instruct the Migration Assistant to keep a copy of the user account that's being replaced by moving it to the "Deleted Users" folder in the Users folder.
    2. Choose to keep both user accounts and rename the account you're copying to a new name and user account name. This will result in the current user account on the new Mac remaining unchanged; the old user account will be copied over with a new user name and account name that you provide.
  2. Make your selection and click Continue.
  3. The transfer process will begin; an estimate of the remaining time will be displayed. This process can take a bit of time, so be prepared to wait.
  4. Once the transfer is complete, the Migration Assistant will restart your Mac. Be sure to quit the Migration Assistant that is still running on your old Mac.
  5. Once your Mac restarts, you'll see the Migration Assistant window reporting that it is finalizing the transfer process. In a short time, the Migration Assistant will report that the process is complete. At this point, you can quit the Migration Assistant on your new Mac.

The Migration Assistant and Moving Applications

Migration Assistant Transfer Status


With the last steps out of the way (see previous pages), the migration of data from your old Mac to your new Mac is now complete. You should be able to log into your new Mac and find all of your user data ready for you to use.

Application Licenses

One of the options in the Migration Assistant is to copy over all of your apps from your old Mac to your new Mac. This process usually goes off without a hitch.

However, there will likely be a few applications that will balk at being moved around like this, and act as if this is the first time they've been installed. This means they may ask you to provide license keys or activate them in some manner.

This occurs for a couple of reasons. Some apps are tied to the hardware they were installed on. When the app checks its hardware base, it can detect that the hardware has changed, so it may ask you to reactivate the app. Some applications keep a license file in some offbeat location that the Migration Assistant doesn't copy over to the new Mac. When the app checks for its license file and doesn't find it, it will ask you to enter the license key.

Luckily, application license problems are few. For the most part, all apps will work just as they did before, but to make things easier on yourself, you should have your license keys ready for any app that needs them.

Applications you purchased from the Mac App Store shouldn't have this issue. If you do see a problem with an app from the Mac App Store, try logging into the store. If the problem persists, you can always download a fresh copy from the store.