How can I adjust the size of the whiteboard？

[mkj13146]

Hello！
I want to adjust the whole whiteboard to 80% of the size of the window, and then the remaining 20% I want to add other elements, such as chat rooms. But I don't want to have rollers. What should I do?
Thanks very much！

[etcy]

I found the setting to save the boards in the server/configuration.js.

Set it to true and problem was solved.