CI 3.x Folder Permissions?

I've updated from CI 2.x-> CI 3.x. It went quite quickly.

I've updated my production server and as expected am getting a permissions error:

Message: mkdir(): Permission denied
Filename: drivers/Session_files_driver.php
Line Number: 136

Where is the docs page that describes what folders need to be set to what permissions? I was just searching the docs for "permissions", but nothing relevant seemed to come up.

Thanks in advance for the info!

Update-- I solved the error message. However, if there's a docs page about folder permissions, I'd like to look at it for further reference.

There's no single page telling you to set permissions for a list of directories, because no such directories exist. They're all configurable, you decide which directories to use ...

The config file contains instructions for this, and so does the Session library docs ...

Excellent. Thanks for this info.