Which O2CB mode should be used for OCFS2 integration with heartbeat? 06/14/2017 – by Mod_GuideK 0 Which O2CB mode should be used for OCFS2 integration with heartbeat? A. user B. dlm C. heartbeat D. kernel SHOW ANSWERSCorrect Answer: A Explanation/Reference: Download Printable PDF. VALID exam to help you PASS.