Some clarifying questions:
What are the numbers you refer to? 3TB drive, is that the source, or the target?
-- The 3TB drive is the target (the backup drive)
What is 112GB? The amount of data to be backed up?
-- Yes, there is 112GB to be backed up.
When you say STOP, I understand there is no error message, but is there any other message, such as "Backing up" (but with no progress ever seeming to happen)? I ask this because this is another scenario that could be described as STOP by some people, and I have no way to know if you are one of those people.
-- During the Time Machine's process, it will start to backup files, and then the status will change to "stopping" after about a minute, it will revery to the status it had before the backup started.
How much free space is available on the source (that is not a typo) drive?
-- The source drive (my Mac hdd) has about 12GB of free space (it's a 128GB SSD)
With which file system is the WD drive correctly formatted? What does Disk Utility show it as?
