about:config browser.sessionstore.interval
for 30minutes set 1800000
src - https://www.servethehome.com/firefox-is-eating-your-ssd-here-is-how-to-fix-it/
ref - https://support.mozilla.org/en-US/questions/926708
ref https://news.ycombinator.com/item?id=12565023
origin - https://www.pipiscrew.com/?p=19026 firefox-is-eating-your-ssd-here-is-how-to-fix-it