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Tiger's Powerful Migration Assistant

by FJ de Kermadec
05/17/2005

Transferring information from an old Mac to a new one has always been one of the tasks I have found most painful when upgrading my computer or operating system. Judging by the number of third-party products and tutorials floating around the Web, I am not alone. Despite this, it seems that we Mac users have it easy, thanks to the flexibility of Mac OS X and Apple's use of innovative firmware features like FireWire Target Disk Mode.

Luckily, the dark days are officially over, since the Mac OS X engineers surprised the Mac world by introducing, along with Mac OS X v. 10.3.4, a new Setup Assistant that also integrated migration capabilities. From the day Mac users first saw this reassuring question "Do you already own a Mac?," they knew the use of unreliable scripts, ugly hacks, and Rogaine to activate the growth of the hairs they had pulled was over. OK, I might be exaggerating a bit on that last one.

Tiger brings us some even better news, as it now ships with a stand-alone "Migration Assistant" that allows you to do all that the Setup Assistant did in an Installer-like, easier-to-use interface. This new assistant, because it is located in the Utilities folder, is now easier to find, and it's easier to extract information from other Macs you own that you've kept to store files. This window-mode, as opposed to the Setup Assistant that worked full-screen, also makes for a much smoother upgrade process, as you stay in control of your computer while the process hums along.

Before We Start

Although Mac OS X engineers have written a reliable, robust migration tool, it's important to keep in mind the limitations of the file transferring process. Indeed, one of the most pleasing side effects of purchasing a new computer or clean-installing your operating system is that you end up with a fresh, perfectly "clean" system that stands unaffected by previous hardware failures, application crashes, or any of the glitches that pop up into our computing routine from time to time.

Therefore, the more information you transfer from an old system to a new one, the more chances there are that you will end up transferring corrupted data or incompatible system files. The Migration Assistant is smart enough to perform some checks and refrain from transferring some files, but it obviously cannot know about the health of every file of every application in every format. The chances of one of these transfers causing real damage to your new installation are low and almost inexistent when transferring simple data files--such as your great aunt's cookie recipe in RTF format, your iPhoto library, or your Address Book database. They get higher as you transfer whole applications (some of them may be incompatible or their accompanying DRM software might get confused by the new environment), or system files (that might contain hardware-specific entries that your new computer does not know how to deal with).

For these reasons, I wouldn't recommend using the Migration Assistant if your previous installation was heavily damaged or corrupted. Instead, use a manual file transfer as described in our Installing Mac OS X v. 10.4 Tiger article. This might take more time but will also make for a smoother transition in the long run.

Also, do not expect the Migration Assistant to save you from hardware failures. Should you have doubts about the physical health of your hard drive, bring it to your Apple Authorized Service Provider instead of subjecting it to a read-intensive duplication process.

What the Migration Assistant Is Not

All you need to migrate your data All you need to migrate your data

Even though the Migration Assistant makes it insanely easy to transfer files from your old Mac to your new one, it's not a back-up or synchronization system. Indeed, there are great applications out there that take care of these steps beautifully, like Carbon Copy Cloner, Apple's very own Backup, or the various updated synchronization services that were introduced or enhanced with Tiger. Every application has its specialty and using the right one for the job is essential, especially when dealing with such important files as your own data.

In a nutshell, Migration Assistant copies from, not to...

Taking Care of Your Old Mac

The first step to transferring your data is, of course, to ensure that your old Mac is in shape and ready to be used as a migration source. As usual, the first thing is to ensure that no minor corruption issue or damaged system files could prevent it from performing as well as it should. This article should provide you with some basic ideas and the information you need to conduct the checks effectively. Although it is Panther-specific, most of the concepts it presents are applicable to earlier versions of Mac OS X and, of course, to our beloved Tiger itself.

Related Reading

Mac OS X Tiger Pocket Guide
By Chuck Toporek

While performing your software maintenance, it is especially important that you pay close attention to privileges. While the default privileges settings should be fine, you do not want some strange "read-only" setting to interfere with the transfer process by blocking the Migration Assistant, in which case some of your files might not be transferred. Usually, this boils down to making sure that Ownership on the volume is not ignored (you can set this through the Finder's Get Info window and it should be the default setting), repairing the permissions through Disk Utility and checking any data folders you might have tweaked yourself. Sure, once a Mac is booted into FireWire Target Disk Mode, privileges are ignored but they will become an issue again once the transfer has happened.

Keep in mind that checking your hard drive's S.M.A.R.T. status is also a good idea at this point as the transfer process can be fairly demanding on mechanisms. You might also want to have a spin with the Apple Hardware Test CD that came with your previous computer to ensure that its FireWire ports are up and running, especially if it has been left in a storage room for some time, collecting dust and mice droppings; but you wouldn't do that to a Mac, would you?

In order to avoid any issues during the process, ensure that both computers are plugged into UPS-protected plugs and that their batteries (if applicable) are charging. This will avoid power cuts during the transfer that can lead to data corruption issues. As no deletion is involved in the migration process, it is very unlikely that the Assistant would lose files but file systems never like to be interrupted while in an unstable state--this is especially true if your older Mac does not belong to the generation that makes use of the HFS+ Journaled file system that Apple introduced with Panther.

Also, ensure that your older computer's firmware is up to date and that it is running an updated version of Mac OS X. While Software Update usually detects firmware updates, you might also want to check the AppleCare Knowledge Base as an additional security. Upgrading your computer's firmware is essential as it will allow the process, which relies heavily on the ability of the target machine to boot into FireWire Target Disk Mode, to happen smoothly, and will avoid confusing your newer Mac, which might not know how to react if the other side misbehaves. Failure to upgrade your firmware can lead to issues ranging from the inability to transfer data between the two drives to freezes.

Should the soon-to-be target machine use an open firmware password, keep in mind that you will need to disable it in order to start it up in FireWire Target Disk Mode. In order to do so, you can follow these steps:

1. Restart your Mac while holding the Option-Command-O-F keys--as in "Open Firmware" 2. Keep these keys depressed until you boot into Open Firmware directly. You might even see a line that says "Release keys to continue!". Note that users who use the full security setting won't even have to use the key combination as their Mac will boot into Open Firmware no matter what. 3. Type "setenv security-mode none" at the prompt and enter return 4. Type your password and enter return 5. Type "reset-all", followed by return to end the session and restart

To re-activate the protection once you will be done installing Mac OS X, simply replace "none" in "setenv security-mode none" by the appropriate level--"command" or "full" and repeat these steps. Open Firmware will have kept your password in mind so you won't be asked to enter a new one.

Note that Open Firmware systematically assumes that you are using a US keyboard--it does not have the necessary information at hand to customize your experience--so you might have to do some re-mapping in your head.

Preparing the Process

Before launching the assistant, ensure that both computers are only connected to the required peripherals--that is an Apple Keyboard, Apple Mouse and power adapter--and that any unnecessary hubs or external drives have been ejected, unplugged and disconnected. Indeed, this will avoid interferences between drives, will make the scanning process easier and, in some rare circumstances involving hardware conflicts might prevent crashes from happening.

It is also important to ensure that the FireWire cable you will be using is up to the task. Indeed, although an iPod or iSight cable (these gorgeously thin white ones) might work, it is preferable to use a data-specific cable--these are usually thicker, provide you with better transfer rates and are less prone to these invisible cuts and bends that can lead to data transfer issues. If you own an external FireWire hard drive, chances are it came with a cable that was made just for that, so you can use it safely.

Finally (and I know I may sound overly cautious but it has its importance), ensure that your computers are placed in such a way that you will not to move them while they do their work. Moving computers whose hard drives are spinning is always a bad idea, even though the latest models have been built to better handle these situations.

Drive-to-Drive Transfers

New options for a flexible transfer New options for a flexible transfer

The Setup Assistant also allows you to transfer information between two drives in your computer. So far, we have assumed you were transferring data from one Mac to another but the general idea remains the same, no matter the method you chose.

Actually, transferring data inside one computer can make for a smooth Panther-to-Tiger transition mechanism if you are a lucky PowerMac owner with multiple drives or have multiple partitions to use. Note that the volume you want to transfer information from needs to be a valid Mac OS X boot volume though in order to be properly recognized by the Migration Assistant. What can be seen as a limitation is actually a feature since volumes that do not contain any system files are likely to be data only ones, that already contain just what you need. Since the Mac OS 9 folder structure did not know about the notion of "accounts" (at least in the same sense than Mac OS X) and allowed users to place applications and files in very varied locations on their hard drives, the Migration Assistant cannot help you transfer files from Mac OS 9 installations either. Given the amount of application upgrading and file re-organizing that is usually involved in these, though, it is probably for the best to not automate that process.

A Warning for FileVault Users

FileVault users might be disappointed to hear that they cannot transfer their accounts to their new machine or installation unless they use the Setup Assistant that pops up when they just finished installing Mac OS X to do so. Indeed, the Migration Assistant, the similar but separate application we are talking about now, cannot take care of these accounts and, while it recognizes them, will not let you select them.

This is easily understandable as the structure of a FileVaulted account makes all your files look like one big file (the FileVault sparseimage) instead of the nested folder structure (the Home containing purpose-specific folders) it should be. Also, by requiring that the Assistant mounts a disk image, FileVault would make it harder for it to draw links between applications and files, making the process a lot risky--plus, there is the whole reconfiguring your new account to be FileVault compliant, which would require that you log out, something you obviously cannot to while the assistant is running. If you are curious about the inner workings of FileVault, this article should provide you with a good overview--things have been improved in Tiger over Panther but the general idea and most of the workings remain the same.

This being said, it is about the only limitation you will encounter with the setup assistant that is equally capable of transferring administrative accounts and managed users--these are structurally speaking more or less the same with different preferences and privileges attached to them.

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