VIM - Config - Indentation - Indentation purely with hard tabs
To indent only with hard tabs, and not with spaces.
set shiftwidth=2
set tabstop=2
NOTE: These settings will result in hard tabs being used for all indentation.
The principle is to set set tabstop and set shiftwidth to the same value, and to leave expandtab at its default value (noexpandtab), and leave softtabstop unset.
shiftwidth affects what happens when you press », « or ==.
It also affects how automatic indentation works.
tabstop changes the width of the TAB character, plain and simple.