It has been migrating for for 19 hours. What is taking so long?

The migration?

A few more details would be great! For example, what have you already done? Or at what state are you blocked?

Here is also a little support article:

http://support.apple.com/kb/HT4796

Have you followed those isntructions and read to some manuals to knwo what you need to be aware of before starting?

Maybe there is a file that is blocked somewhere. You should retry the process, however under following conditions:

- first restart the computer and login with your account

- then eliminate as many startup applications and utilities as possible

- clean the desktop (put files in "My Documents", etc...)

- check powersaving settings, and remove any "turn off hard disk" options (use maximum performance)

- restart the computer again

- launch the migration tool, nothing else

- hope for the best

I've been trying to migrate an iMac to iMac on Mavericks since yesterday morning. Twice using ethernet which stayed on " less than a minute " all night. Tried using a Thunderbolt cable which did not work at all. My latest attempt is using Time Machine as the Source . The original source iMac is 21.5" was purchased in 2011 as and the new iMac is a 27" Fusion drive . I've migrated many many machines since I've been on the MAC platform since the 80's and have never experienced this long a migration on 2 fairly fast machines.