building light takes space from my c drive

hey guys!
i don’t know if this topic has already been discussed but i’ll give it a go, and i hope you will forgive me.

so the idea is this:
i have installed UE4 on my D disk, and all my projects are there, however when i build lighting for a level, the space on my C disk is eaten up. from 6gb i go to 200 mb.
what the hell is happening and how do i stop this?
Please help!

You are probably running out of RAM and the OS is caching to disk.

Look at your appdata/local and appdata/roaming, you will find 4 directory’s with Unreal Engine in the name. Create symbolic links for each one of them and link them to you D disk.
Here you find more information about symbolic links:
This worked for me. When you create a symbolic link it links everything in the directory to a differend location. So when Unreal Engine saves data into this folders it doesn’t take space anymore in you C disk and locates everything to you D disk. I hope this will solve your problem.

Since 4.18 you can manually specify where you want to have the cache folder in your Editor settings under Global. So won’t have to make a Symbolic Link anymore.