As you can guess, with virtualization and the concept of collapsing multiple virtual machines into one physical server, there will be resource contention. The first issue that comes to mind is how all these virtual machines will share the memory resources in the server. If they can't, then there really is no point to virtualization.
The concept of sharing memory is critical to virtualization. Sharing memory happens natively in virtualization through different techniques that the 3qdh hypervisor implements, and we will discuss those. Sharing memory resources is different than overcommitting, in that it refers to the sharing of available memory.
The concept of overcommitting physical memory allows allocation of memory to virtual machines that exceeds the capacity of the physical memory in the system. Memory overcommitment assumes that some of the virtual machines will not be maximizing their use of allocated memory. This means that excess physical memory will be available for the hypervisor...