U-tube
U-tube is a dynamic memory management tool for Xen virtualized envi
U-tube monitors the memory usage of each VM to detect its memory pressure, and periodically adjusts its memory allocation via memory hotplug. It is implemented as a loadable device driver to coordinate guest OS’ MMU with underlying hypervisor. In contrast to the popular ballooning mechanism, memory hotplug can dynamically expand a guest OS’s physical memory space beyond its maximum configured at booting time.