Remove the man-db
package
sudo apt remove man-db --purge
Remove mandb
directories
sudo rm -rf /usr/share/locale/
sudo rm -rf /usr/share/man/
sudo rm -rf /usr/share/doc/
create a file /etc/dpkg/dpkg.cfg.d/01_nodoc
with below content.
# Delete locales
path-exclude=/usr/share/locale/*
# Delete man pages
path-exclude=/usr/share/man/*
# Delete docs
path-exclude=/usr/share/doc/*
path-include=/usr/share/doc/*/copyright