CIRCLE / vmdriver

The OS prefers cache instead of kvm processes, swapped out memory pages of VMs.

These might helps to solve it:

• https://wiki.archlinux.org/index.php/Swap#VFS_cache_pressure
• http://pubs.opengroup.org/onlinepubs/007908799/xsh/mlockall.html
• memory pressure
• https://libvirt.org/formatdomain.html#elementsMemoryAllocation
• https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/virtualization_tuning_and_optimization_guide/chap-virtualization_tuning_optimization_guide-memory (the whole chapter)