hoakley November 30, 2018 Macs, Technology

**Setting up a new (or repurposed) Mac:** 2 Migration Assistant

Of all the methods of migrating settings, apps and other files to a new Mac, the best is Migration Assistant – when it works. This article explains what it does, how it works, and where it can go wrong. My aim is to help you decide whether to try to use it for any given migration. Apple does provide a Windows partner; as I have no experience of using that, I will confine this to migrating between Macs.

Migration Assistant consists of a common front-end to what are in effect two quite different apps: one which acts as a client, requesting and installing files on your new Mac, the other working as a server which delivers those files from your old Mac. These are run with elevated privileges, effectively from outside any existing user account, and with all user apps closed.

In fact, Migration Assistant is even more complex than that, as it can perform migrations from Time Machine backups rather than a server.

When to used to its full extent, Migration Assistant will migrate:

complete user Home folders, including all settings in ~/Library;
all apps in /Applications and its sub-folders such as Utilities, except Apple’s apps which are protected by SIP;
settings and support files in /Library;
support files in other hidden folders.

Migration Assistant runs with SIP turned on, as in normal use, so cannot migrate protected parts of macOS or related files, including the great majority of /System/Library. On a new Mac, they are already pre-installed.

The easiest way to run Migration Assistant is when it is offered during the standard macOS setup sequence, when you have first powered your Mac up. It is then presented as just one of the several steps required to configure your Mac and its primary admin account. However, it is also most likely to be unable to complete its tasks at that stage. You can run Migration Assistant at any time thereafter, so shouldn’t be panicked into doing so at that first asking.

One common problem is when your old Mac is running the latest version of macOS, and the new one has an older version pre-installed. In most cases, what happens is that you are unaware of the disparity in macOS, Migration Assistant spends a long time examining how much there is to migrate, and finally informs you that it cannot help until the new Mac has been upgraded to the same version of macOS. There’s no easy way around this as far as I can tell, and in those circumstances you will have to configure the old macOS on your new Mac, upgrade it as soon as possible, then run Migration Assistant after that.

Migration Assistant therefore works best when:

both Macs are running the same version of macOS (and Migration Assistant);
there are fewer items to migrate. Hundreds of thousands seem OK, but millions may overwhelm;
it is migrating the primary admin user account from your old Mac to the primary admin account of your new Mac;
there are no disk errors, damaged folders or files on source or destination storage;
the old Mac has no custom extensions or other software which might upset the new Mac;
the user names, particularly the short version used to name the user’s Home folder, are the same;
an old user account is entire and doesn’t use any ‘tricks’ in its Home folder.

You can improve Migration Assistant’s chances of success by preparing your old Mac to address those, before starting the migration.

Mojave’s Migration Assistant auto-detects the best connection between the two Macs, and should use the fastest available. Although that is important, and something within your control, the time required to migrate is also heavily dependent on the number and total size of the files that have to be moved.

At the start of the process, Migration Assistant on your new Mac looks for Migration Assistant on your old one (unless migrating from a Time Machine backup). As soon as you have opted to use this feature, you need to open Migration Assistant on your old Mac and set it to supply the files To another Mac, acting as the server. The app running on your new Mac (the client) then obtains listings of those files which can be migrated from the server. This enables you to decide what to migrate, and Migration Assistant to determine whether there is sufficient free space.

The client Migration Assistant checks with a blacklist of apps and other software, and won’t migrate items on that list. The list is stored at /System/Library/PrivateFrameworks/SystemMigration.framework/Versions/A/Resources/MigrationIncompatibleApplicationsList.plist, and Apple does update it occasionally. The current version, which should have been silently updated on all Macs running Mojave, is 10.14.177 dated 29 October 2018.

If you’re running Migration Assistant during initial configuration, any migrated primary admin account is by default used to configure and populate the new primary admin account. When you run Migration Assistant after initial configuration, you’ll be prompted to choose whether to fold any migrated account into the primary admin account on the new Mac.

Although it may be tempting to turn a migrated account into a secondary account on the new Mac, that can cause problems. Much of Unix, hence macOS, identifies different users by number, with the primary admin account normally being 501. If you end up with a secondary account, that will be numbered 502, which means that all files and folders associated with that account will bear that number. If you’re then tempted to try to remove the primary admin account, number 501, that can lead to utter chaos. Only use migration to create and populate secondary accounts if you’re sure that you know what you’re doing.

The good news is that Migration Manager does do a very effective job of folding your old Mac’s primary admin account into the primary admin account on your new Mac, if that is what you opt for. This ensures that keychains and other vital user data are transferred correctly, and the new primary admin account should be fully ready to use.

If you run Migration Assistant after initial setup, it works quite differently from a normal app. It first logs out of your account, and prompts you for an admin user’s password so that it can obtain the privileges that it needs. This involves closing all open apps, and may result in the unmounting of some external volumes too. To support migration from a Time Machine backup, volumes containing potentially suitable backups aren’t unmounted, and Migration Assistant normally checks those to see if they are suitable sources for migration.

Apart from the refusal of migration because of version incompatibilities, the most common failure in migration using Migration Assistant is its apparent hanging in the midst of a migration. If this occurs before any files have been migrated, the best way ahead is to abandon migration at this stage and continue to set the new Mac up as a completely new system. Once that has completed, and all updates have been installed, try again using Migration Assistant.

If Migration Assistant fails after it has started to install files on the new Mac, the migration will at best be incomplete, and at worst may have made the new Mac unusable. If that occurs, and the new Mac remains usable, it should be possible to complete the migration later. If all else fails, it may be necessary to restart into Recovery mode, and re-install macOS from there.

The most common problems after an apparently successful migration relate to the transfer and installation of extensions and other software, or even preference files, which prove incompatible. The probability of this is greatly reduced by migrating between Macs which are running the same version of macOS. In theory, they should then be completely compatible.

In practice, clashes and strange mis-settings can still occur, most probably when the types or models of Mac are very different. Use Migration Assistant between two desktop Macs running 10.14.1, and you’re unlikely to suffer such issues. But go from an older macOS on a Mac mini to Mojave on a MacBook Pro 2018 and you are more likely to encounter glitches.

You can circumvent those by limiting what you migrate, but that reduces the value of Migration Assistant, and leaves you with more work to finish off. I haven’t yet located any migration log left by Migration Assistant listing either what it did copy across, or what failed. At the end of a migration, a list is provided of those items which it expected to copy but didn’t, but this doesn’t seem to be written out to an accessible file.

One potential workaround if you suspect that there could be problems is to migrate from a Time Machine backup instead of the old Mac itself. This is generally considered to be smoother. If you can connect that backup to your new Mac using Thunderbolt, or even USB 3, it should also be reasonably swift.

Finally, Migration Assistant isn’t the quickest way to move files. Allow plenty of time, several hours at least, unless you’re moving very few apps or documents.

Apple’s current articles about Migration Assistant include:
Set up your new Mac (very basic)
How to move your content to a new Mac (introductory)
Restore your Mac from a backup (migrating from a Time Machine backup).

24Comments

Add yours

1

Matt on November 30, 2018 at 6:45 pm

Migration Assistant has checkboxes to migrate [x] Applications, [x] Documents, and [x] Preferences. I’d be curious to know more about the meaning of each. In my case, my migrated Mac was messed up by an ancient iTunes audio plugin—maybe not migrating [x] Applications would have mitigated that? I also wonder if migrating the migrated machine to itself (using a Time Machine backup, and excluding [x] Applications) is a way to flush old binaries, though I’m sure there are easier ways to do it.

LikeLiked by 1 person
- 2
  
  hoakley on November 30, 2018 at 6:53 pm
  
  I’m afraid that Apple doesn’t define these categories.
  Applications should include apps installed in /Applications and its sub-folders, but not elsewhere, plus their supporting files e.g. in the Application Support and similar folders, in /Library and ~/Library.
  Documents should include all the contents of your Home folder ~/ except for ~/Library.
  Preferences should include all the contents of /Library/Preferences, and ~/Library/Preferences.
  The only effective way to prevent that sort of problem is to spend some time performing rigorous housekeeping and weeding of your old Mac before migrating. Executable code can lurk in all sorts of places. Another tool which you may find useful is my free 32-bitCheck, which will list 32-bit only code of various types as well as regular apps.
  I’m afraid this this is one of the penalties of using Migration Assistant.
  Howard.
  
  LikeLike
3

EcleX on December 1, 2018 at 6:05 pm

You said “Migration Assistant therefore works best when…” What are the alternatives otherwise sorted by reliability? Thanks.

LikeLiked by 1 person
- 4
  
  hoakley on December 1, 2018 at 6:13 pm
  
  I’ll be getting onto that in the next article. Essentially, you are then looking at a manual migration, in which you copy all the files which you want to migrate. How you do it depends on which file(s) you are copying. For example, to sync your keychain, the best way is to use iCloud Keychain Sync, or a third party equivalent. You can sit there copying and pasting items between an old keychain and you new one, but it’s painfully slow.
  For preference files, you can perform a simple copy, but open preference files will then probably get overwritten by the new one.
  So again there isn’t a simple and crisp answer. I’ll go into this more next week.
  One old technique which is now generally doomed to failure is to clone your old system to an external drive, move that, and try to start your new Mac from that. I think that will cause offence to any T2 chip!
  Howard.
  
  LikeLike
5

EcleX on December 4, 2018 at 3:33 pm

Thanks. I want to make a full migration or cloning, including all. The “old technique” is also what I want to do, which is extremely useful. I do not like the T2 chip. When you have nothing to hide, it is a waste of energy and resources. No, i do not want encryption. Ever. Apple should allow to disable completely T2.

LikeLiked by 1 person
- 6
  
  hoakley on December 4, 2018 at 8:10 pm
  
  Thank you.
  I don’t even notice the T2 in this Mac. Why do you think that you don’t want it?
  Tomorrow morning (Wed) I finally tackle manual migration. I look forward to your comments.
  Howard.
  
  LikeLike
7

EcleX on December 5, 2018 at 7:44 am

The T2 chip increases the probability of losing everything if something fails (T2 itself, motherboard, etc). You cannot repair the Mac yourself. Not even third-party repair services. I think all that is even illegal. Additionally, the iMac Pro has two SSD blades in a RAID 0-like configuration, which also increases failure rate more than twice if one blade or controller fails. Yes, I know some SSD can be quite reliable, but they do fail as well. I purchased five iMac 5K 27-inch (top configuration) on mid 2017 and one of them shows erratic random boot failures, which points to GPU, which is soldered, requiring full logic board replacement. I cannot remove the SSD and replace it by other because it would void warranty and besides it is really tricky and damage-prone by unexperienced users. Not good either.

And back to topic… I want to boot from external drives without any problem. That is great to repair disks (DiskWarrior, etc). I also want to make full backups (SuperDuper or Carbon Copy Cloner, etc) and boot from them if needed, when disaster strikes or whatever.

And last but not least, I do not want to destroy planet Earth: I do not want to waste energy encrypting everything by default via T2 chip when I have nothing to hide at all. Making it optional would be the bests approach. Besides, all that forced encryption can make difficult or impossible to repair (DiskWarrior, etc) or recover precious data (manually, Data Rescue, etc) if disaster strikes. I do not want Apple to tell me how to use my Mac. That is why I do not want iOS either. Do not get me wrong, I love the Mac, but the latest Apple moves are not acceptable. I want freedom to decide what I do or not do with my Mac. Options are good, but not forcing people in any direction.

LikeLiked by 1 person
- 8
  
  hoakley on December 5, 2018 at 9:17 am
  
  I tackled those issues in this article recently.
  If anything on your logic board fails – and almost everything is now on a single logic board – then it doesn’t matter whether it’s the CPU, T2 chip, soldered-on memory or SSD. The whole logic board has to be replaced. How many 3rd party repairers are capable of removing such soldered-on components, obtaining supplied of replacements, and replacing them?
  We all rely on backups. If a Mac’s logic board has to be replaced, whether or not it has a T2, you will have to restore from your backup to rebuild your repaired Mac.
  If your Mac has T2 chip, you can still boot from an external drive, but before doing so have to enable that in Recovery Mode. There’s nothing to stop you from leaving that as its setting if you really want.
  I love the idea of wasting energy by encrypting/decrypting: as the T2 is actually the SSD controller, I suggest that you are trying to save the planet with an infinitesimally-small theoretical saving which doesn’t even register in the Mac’s total power consumption. I’d love to know how many microwatt-hours that might accomplish!
  But overall, if you want the freedoms which you say, Apple products have always been the wrong ones for you. Apple has never designed or built its Macs to be user-repairable, or to give you the freedom to run whatever hardware you want. And you certainly won’t be able to run the current version of macOS reliably on any such Hackintosh.
  Sorry – that’s been the way that the Mac is.
  Howard.
  
  LikeLike
9

EcleX on December 5, 2018 at 10:11 pm

I know, but I think that I did not explain myself. What happens if T2 is active, the Mac does not boot and DiskWarrior cannot repair it since you cannot boot from external drive? I meant that.

And as I said, I love the Mac. That is why I do not use the horrible Windows or the ultra-horrible Linux. And by that I mean the intuitive or complicated interface. My main point was that Apple should not force users into its features, but offer the option to use or not them.

Yet another off-topic example is the colored folders that were extremely useful to spot them easily, and now are a tiny color dot that is hard to find when you have many items. That reduces productivity. Apple does things right sometimes, but not others. And said said, options are good, but only as options to choose or not them.

LikeLiked by 1 person
- 10
  
  hoakley on December 5, 2018 at 11:18 pm
  
  Unfortunately, for the time being, you can’t use DiskWarrior to repair or rebuild any APFS volume. As far as I’m aware, the only method of checking and repairing an APFS volume is using Disk Utility, and the best way to do that is in Recovery Mode. So whether you have a T2 chip, what the Secure Boot settings are, and whether your startup volume is encrypted are all irrelevant – if you’ve got a problem with your boot drive, the only solution available is to start up in Recovery Mode.
  Whether and when third-party tools like DiskWarrior will ever match Disk Utility on APFS remains to be seen. Until then, having a T2 chip and using Secure Boot make no difference to your ability to recover your startup disk.
  I don’t like that situation, but like you the alternatives are far worse. And I’m just loving this iMac Pro!
  Howard.
  
  LikeLike
11

EcleX on December 6, 2018 at 8:04 am

Thanks. I meant, once DiskWarrior 6 is released (they are making progress on that and will release soon, since Apple published APFS specifications in September). Likewise, TechTool Pro 11 for Mojave will be released this month, and Drive Genius 6 will follow also.

So, once these utilities are released, T2 chip may block recovering dada. That is what I meant. As said, it would be fine for me if Apple made optional the use of T2, not compulsory. That was my main point. Options to choose from are good. Forcing people is not good. Because not all users have the same needs or desires.

And ultimately, customers have paid for the computer, which is no longer Apple’s property by user’s property. To some extent, as said, some of these practises may be even illegal, and some countries have already started legal actions against Apple because of that. Do not get me wrong. I support Apple, but I do want it to change some of its policies as well.

LikeLiked by 1 person
- 12
  
  hoakley on December 6, 2018 at 4:56 pm
  
  I too have read the “APFS Documentation”. It is sketchy at best, incomplete in many respects, and doesn’t cover encrypted formats or Fusion Drives.
  I think it may be some time before any third party disk repair utility matches the performance of fsck_apfs, which is what Disk Utility uses.
  Another issue which you need to consider is that the T2 chip doesn’t just encrypt, but it is actually the disk controller. This is how its encryption performance is so good: encryption/decryption are actually part of the low-level access to the SSD. All the indications are that any software accessing the SSD in any way will inevitably pass through the encryption stage, so it shouldn’t be something which disk repair utilities even worry about. When they access the volume metadata, the T2 will automatically handle the encryption/decryption just as it handles disk access, as part of that.
  The reason that this can’t be an option is that the moment it is, it opens a vulnerability (or, rather, many). And making every Mac vulnerable for the sake of a few users is probably not a good move for anyone.
  I don’t think the legal actions concern the use of the T2 chip – most that I have heard about are over the right to repair. I have no problems with that right, and think it’s important, even if essentially impractical for many modern computers.
  Howard.
  
  LikeLike
13

Setting up a new (or repurposed) Mac: 2 Migration Assistant – The Eclectic Light Company – Jerry's Mac Blog on February 15, 2019 at 6:08 pm

[…] Source: Setting up a new (or repurposed) Mac: 2 Migration Assistant – The Eclectic Light Company […]

LikeLike
14

Chris Smith on March 21, 2019 at 2:11 am

This is a great article but I thought it seemed like overkill to do all these manual steps.

I was migrating from my iMac 2017 with a 1 TB drive to a MacBook Pro 15” 256 GB drive. I had an external usb drive with a time machine backup of my iMac.

Obviously I could not do a time machine backup restore because of the different drive sizes. Instead I went thru the migration assistant and chose the time machine backup on the external drive. After going thru and checking this and that and getting the size below the 256 GB mark (238 GB actually), it kept erroring out with the “sorry” screen listing everything that failed. After that the OS would not boot. I ended up having to Cmd+R on reboot and go into recovery console and erase the drive, reinstall macOS, login and update the os, then I pre-created the user that existed on my iMac (the user I previously tried to migrate).

Then re-ran the migration assistant, I had to first migrate my user folder (unchecking those folders that are synced on iCloud like Documents etc.). I then logged in under the user and manually deleted things I didn’t need out of the user folder to free disk space.

Then to get my system settings, applications, network settings etc, I ran thru the migration assistant a second time and this time checked everything BUT the user folder.

These multiple runs of migration assistant seemed to work. I suspect the migration assistant was miscalculating the disk storage so it was trying to write more to the MacBook 256gb drive than it could store even though I had unchecked things and got it to a size migration assistant said would work.

I imagine just putting a 1TB drive into the MacBook Pro and doing a time machine backup restore would have saved me some hassle although the 1TB drive is about +$800.

Hope this comment helps for others in the future.

LikeLiked by 1 person
- 15
  
  hoakley on March 21, 2019 at 6:32 am
  
  Thanks.
  As I write above, you may not need to do any manual steps at all – for many, migration during initial setup should work just fine now. It does seem to have improved considerably.
  However, if that does fail for any reason, or isn’t possible, there are the manual methods which I describe here. You don’t have to use them, and running a second pass after setup can be useful, or may not be needed at all when the first pass works fine.
  Howard.
  
  LikeLike
16

BillyGuy on May 18, 2019 at 7:42 pm

Hey Howard ! And thanks a lot for all you do, I use regularly your softwares 🙂
I have a quick question, there is an option in migration assistant for using a web server. Have you had the chance to try it ?
I have a few machines to migrate, now I use a hard drive, it is going ok but I want a way to do it several machines at the same time, even if it takes a little longer.
I’m wondering what way should it be on the server side. Does it need to be a disk image, should it be directly the /Library /users folders ? Until now I didn’t find yet any documentation, if you have any info I’d appreciate !
Thanks in advance

LikeLiked by 1 person
- 17
  
  hoakley on May 18, 2019 at 7:50 pm
  
  Thank you.
  I haven’t come across a Web server option, which would seem strange, but there have been options to use former macOS Server systems for migration.
  If you really need to migrate multiple Macs from the same setup, the quickest way to do that would be using one external drive connected to each Mac which you want to migrate. Simply clone the ‘parent’ drive onto those external drives using Carbon Copy Cloner, and that should allow you to have them all migrating at the same time.
  I’m pretty sure it’s not possible to migrate more than one Mac at a time from a migration source – the assistant won’t do that.
  Howard.
  
  LikeLike
18

BillyGuy on May 25, 2019 at 7:29 am

Apparently the mail notification doesn’t work, sorry I didn’t see your answer until now.

When you have to choose the source, there is a bouton on the down left side that says “other server”, when chosen, one sees that it’s possible to use an AFP (excluded with APFS), SMB, or HTTP server as a source.

By the way, I did a screenshot of the window but can’t find the picture, it’s not on my main (and only) GUI user, and it’s not on root’s Desktop either, do you know where they are saved ?
TIA

LikeLiked by 1 person
- 19
  
  billyGuy on May 25, 2019 at 7:34 am
  
  So sorry, I didn’t use the reply button…
  
  LikeLiked by 1 person
- 20
  
  hoakley on May 25, 2019 at 8:26 am
  
  Sorry: I have no control over that feature in WordPress.
  I’d be surprised if AFP works at all now; Apple doesn’t document any of this as far as I can see, and I’m afraid I can’t check them either.
  The best way to find that screenshot is to use Spotlight, searching for ScreenShot. It could be anywhere!
  Howard.
  
  LikeLike
  - 21
    
    billyGuy on May 25, 2019 at 8:39 am
    
    Funny, now the notification worked ! I just received an email, and you know what ? I didn’t check “Notify me of new comments via email” ! 🙂
    
    My only question is how it should be “presented” to the client machine, I’ve tried without success until now, but I’ll try to find time next week
    
    AFP should work with HFS+ volumes I guess, I’m still getting better bandwidth with volumes shared in AFP than with SMB on EL capitan. Not true with Mojave where SMB implementation is better, and almost catches up on average.
    But this is another subject 🙂
    
    Thanks anyways, I’ll try to update my answer if I find something interesting
    
    LikeLiked by 1 person
    - 22
      
      hoakley on May 25, 2019 at 9:56 am
      
      I’m sorry, I have no idea how it should be presented to a client. I would suspect that this is a hangover from macOS Server.
      I don’t think that AFP support is dependent on the file system – but the version of macOS. It was deprecated in Sierra, I think, and gone in High Sierra?
      Howard.
      
      LikeLike
23

billyGuy on May 25, 2019 at 8:47 am

Btw, screenshots appear with a different name, like when you do it on the login screen, the names are not localised and are called : LWScreenShot+date

LikeLiked by 1 person
- 24
  
  hoakley on May 25, 2019 at 9:56 am
  
  That’s why I suggested you search on ScreenShot. I couldn’t remember where I found them before.
  Howard.
  
  LikeLike

·Comments are closed.

Share this:

Related