I have MacBook Pro (Retina, Mid 2012) and OS is in a separate partition of 50GB. and other partition empty with over 200GB.

[muralikavi]

I have MacBook Pro (Retina, Mid 2012) and OS is in a separate partition of 50GB. and other partition has files and have empty with over 200GB. When I attempt to update SIERRA, I get message there is no space. I am getting frequent messages saying no space even though I have over 200GB space. I want to reformat to Factory setting and get rid of partition. Pl let me know if partition will remain or go away when set to factory setting. Further when I back up using TIME MACHINE AND EXTERNAL Drive, will I need loading OS like we do in Windows?

 

[popatim]

You could shrink or remove the 200gb partition and then expand the 50gb partition using Disk Utility which can be found in Applications>Utilities.
Please make a backup first, if you don't already have one, in case things go horribly wrong.

 

[muralikavi]

Thanks