Q: Migration assistant won't work via thunderbolt in Mavericks

I'm running the same two machines as you and had the same problem. Fix was to ensure the thunderbolt cable was fully in-  sounds stupid but the white collar needs to be flush against the imac housing. Mine stopped halfway in and felt like it was in.

I ran migration assistant in T disk mode on the iMac, but as someone else mentioned only a 176kb transfer came up. Fix for this was to repair disk permissions in disk utility on BOTH old and new machines! New machine had lots of incorrect permissions for some reason.

Took around 20mins to do my full transfer by Thunderbolt.

You saved me a lot of aggravation today, buddy.

Thanks!

Juliet

I'm trying to migrate from a mid 2011 Macbook Air to a new mid 2014 Macbook Air. I successfully put the old one in target disk mode. Begin the migration. Status shows transfering. I come back later, new Mac is off. Start it up, nothing has been migrated! Same experience twice. Now I'm backing up with Time Machine to a Thunderbolt RAID, hopefully migration assistant will work with that.

Yes this works Thanks Peter! After a couple of hours, I've found the solution. I'm doing this slightly differently. The migration is from a MacBook hard drive removed from the MacBook with no firewire/thunderbolt port and hence no target disk mode, it's placed in a  USB dock.

Matt

Adding another thanks to Peter. My wait time wasn't as bad as some of the others, but after spending 7 hours transferring files only to have it lose Internet access at the "under a minute remaining" mark I went and bought a thunderbolt cable. Couldn't get it to work until I followed your directions. Done in less than five minutes!

thanks for taking the stile to spell it out so clearly.

@Peter thanks for the 25 hours saved; @apple this is a load of nonsense; how can this bug be still unresolved!

Just had a similar issue with a an Air and a brand new iMac both running 10.9.4.  Connecting via a known good thunderbolt cable would not work. Looking at thunderbolt in the System Information app showed that both sides "saw" the cable (the serial number was displayed).  The solution was to open up the Network system preference which immediately detected a new device and then select the thunderbolt adapter and click apply with the.  Both sides assigned themselves IP addresses ("Using DHCP" was the pull down entry for "Configure DHCP" .  Migration assistant worked fine afterwards.  I don't know if just opening up the system preference was enough or if the last step was also necessary.

Thank you so much Peter! You saved me nearly 24 hours. First tried to fix the startup disks on both of the computer, with no luck. This technique, namely waiting to plug in the thunderbolt cable to the destination Mac until after migration assistant was already searching did the trick.

Thanks Peter. Plugging the thunderbolt cable in after starting Migration Assistant worked like a charm. It saved me so much time.

I have a similar but different problem.   I am going from a 2011 to early 2013 MBP's.  Both on same version of mavericks.  Did some of the suggestions here and finally got the new MBP to see the old one.   The old one had the main drive and an added "optidrive" that has a superduper backup system on it.  

Here is the problem.... The only drive the the migration assistant can see is the superdrive and not the main drive on the old mac.?

I am erasing the backup system on the optidrive to see of that makes a difference,

I believe I have resolved this issue.

The machine that I wanted to use as the source for migration was at 10.9.4 and the other machines were below that version. Once I updated the other computers they recognized the other computer instantly and migrated in less than 14 minutes a piece.

Thanks so much guys!Finally was able to gOOgle with the right keywords and landed here! Just wish there was a way to get Apple to correct their document for those naive users who read it

But now it says 20 Minutes remaining (vs 35 hours via Wifi) so I am Happpy!

PterSels, I followed your advice. It worked. You saved me a 16 hour data  transfer, excluding applications and computer settings. Thank you!

For anyone else reading this, I also did the following steps prior to following PeterSels' steps. I migrated data from a 13" MBP July 2011 model ("source") to a 15" MBP Retina August 2014 model ("destination").

(1) Set up the destination (new) laptop with an admin user account, which I deleted after my data and user ID had been migrated.

(2) Made sure Mavericks' latest version was installed in both the source and destination computers via the "Apple" ==> Software update mechanism.

(3) Verified permissions and the disk on both the source and destination laptops via Disk Utility. (What heck, might as well make sure the new one was OK.) I had to repair the disk on my source/old laptop.

(4) Ran the MacCleanse app on my source/old laptop. (MacCleanse is purchased separately, and does not come installed on the MBP.)

I then switched off the wi-fi on the destination MBP, per PeterSels' advice, above, and followed the steps he listed using a Thunderbolt cable between the two machines. His steps worked just fine.

It took 3.5 hours to transfer the data, but that was better than the 16 hours via wireless I had been quoted when neither MBP noticed I had the Thunderbolt cable plugged into both of them.

Thanks again for the advice.

Lifesaver Peter! It only took me 5 hours to find your solution but it saved me from 250 hours to 3 hours of transfer time (and my sanity too)!

After a similar problem I found http://www.hardturm.ch/luz/2014/02/fixing-os-x-10-9-mavericks-migration-from-ext ernal-volume/ which explains that since Migration assistant logs you out, it also unmounts external disks. They have a solution in using ssh and command line stuff to mount the needed disk remotely, but someone in the comments had a simpler solution: do not plug in the external firewire disk until after launchine Migration Assistant. So before running MA, eject the external disk that you want to migrate to the new machine (and unplug it) then start Migration Assistant and after selecting "migrate from an attached disk" THEN plug in the disk. It worked for me.