How to measure memory utilizatin of guest when dommemstat reports "RSS" is more than "ACTUAL"? Following is the output on RHEL 6.6 # dommemstat 1 actual 16777216 rss 16890372 # dommemstat 2 actual 16777216 rss 16460516 I found following article on Redhat which suggests that this is normal/expected? https://access.redhat.com/solutions/2017943 Now we use following formula to calculate the memory utilization. mem_util = (rss/actual)*100 now this gives more that 100% as the result. We use the libvirt library to call the virDomainMemoryStats. (which is the same used by the "virsh dommemstat" command) If we can't use the RSS as the "used memory", what else should be used to calculate the same? What is the ideal approach to report memory utilization of guest from the KVM host?