The ksmd daemon will take one or two minutes to start deduplicating memory and will require several minutes to reach stable state. During the boot phase your HN could start swapping if you have heavily overcommitted your RAM. You might want to use more aggressive settings (higher <code>pages_to_scan</code>, lower <code>sleep_millisecs</code>) at the beginning , effectively trading CPU utilisation for less chances of disk swapping, and then relax them after 10 mins or so. Others suggest Another possibility is to place your swap onto an SSD drive.