Cracking is common in some RV floors - especially the ones that come with cheap vinyl that are only glued/stapled on the perimeter. The ones that comes with better grade linoleum that are fully glued are suppose to be less susceptible to cracking.
My linoleum didn't crack but when my carpet got old/tired I installed Allure flooring which was a fairly easy install - floating floor. It's a popular product used by many RVers - use forum search engine.
http://www.everything-about-rving.com/what-can-we-do-to-stop-the-linoleum-floor-in-our-rv-from-cracking.html