Blender's /tmp/ folder is suddenly empty I work on an iMac. I am trying to render a fluid simulation that is very slow, and decided to do it in several batches.

For the first batch, I rendered frames 1-100, and had to stop rendering to perform other operations on my machine. I checked the /tmp folder to verify the result and it looked fine.

Then I rendered frames 101-200 and had to save the blender file and completely restart the computer, because another process made the machine crash. 

After restarting, the /tmp folder for Blender didn't contain any rendered files:



I also checked the Trash, but there was nothing in there either.

Were these files completely erased from my machine after the restart? Or were they moved?

I am sorry if this sounds like a noob question, I've never used a /tmp folder with any other app, and I usually create 3D projects and animations that are rendered fast enough by Blender that I don't have to restart my machine during a render. 

It's kind of sad if this default location just clears itself automatically upon restart, without even a dialog box warning or asking the user (but Blender's not really good at dialog boxes...). But if there's a way to change/act upon this behavior ("ask before delete" or "never delete tmp folder" options?), I'd love to know.
Do not render to a tmp folder!

Set a proper folder to render your files.

tmp folder is... For temp files... When the computer restarts it gets rid of temp files. This is not an issue with blender but the operating system.