System for dynamically adjusting memories of virtual machines

The invention provides a system for dynamically adjusting memories of virtual machines. The system comprises N servers and a memory management and distribution platform; each server is communicated with the memory management and distribution platform through a respective network communication interface; N virtual machines and a memory adjusting module are constructed on each server; a memory acquisition module is established in each virtual machine and used for acquiring the practical use value of the memory belonging to the virtual machine in the present moment in a timed manner and transferring the practical use value of the memory to the memory management and distribution platform through a virtual serial interface; the memory management and distribution platform judges whether the memory distribution condition of the special virtual machine is necessary to adjust or not according to a pre-set memory management strategy; if the memory distribution condition of the special virtual machine is necessary to adjust, the numerical value of the memory to be adjusted is calculated; and a memory adjustment instruction is generated and sent to the special server where the special virtual machine is. The memory distribution conditions of all the virtual machines on the plurality of servers can be dynamically adjusted in real time in the same operation environment; and thus, the resource utilization rate of the whole system is increased.