I'm running my first backup of my iMac using Time Machine to a Synology NAS with alocated space (bootcamp excluded and not running any virtual machines). The problem I am having is that the amount of data supposedly being backed up keeps increasing while the progress bar seems to stay in one place, with Time Machine unable to give a calculated time remaining. This started after around 20 hours of backup that seemed to be progressing fine and has now been continuing for the past few hours. Initial estimate was approximately 750gb and now it is showing 870gb with no sign of stopping. Is this normal for a first backup? ie, Time Machine just has trouble giving a proper estimate for data and time of backup? I have seen other mentions of this problem, but none that really give a straight answer.