How can I scroll up more (increase the scroll buffer) in iTerm2?

macOS default terminal (not iTerm2)

macOS 10.15.7

1. open Terminal
2. click Prefrences...
3. select Window tab
4. just change Scrollback to Limit number of rows to: what your wanted.

my screenshots

There is an option “unlimited scrollback buffer” which you can find under Preferences > Profiles > Terminal or you can just pump up number of lines that you want to have in history in the same place.

Solution: In order to increase your buffer history on iterm bash terminal you've got two options:

Go to iterm -> Preferences -> Profiles -> Terminal Tab -> Scrollback Buffer (section)

Option 1. select the checkbox Unlimited scrollback

Option 2. type the selected Scrollback lines numbers you'd like your terminal buffer to cache (See image below)