In this paper, the author propose two novel algorithms called BPX and IDD that are able to provide the concept of buying bulk capacity to a cloud customer. These algorithms dynamically allocate the overall capacity between VMs based on their demand and user-set importance. Both algorithms are highly scalable and are designed to serve in a large scale environment. Their analysis shows that BPX is able to meet all the desirable properties in providing the concept. They implemented the prototype of BPX as part of VMware’s management software and showed that BPX is able to closely mimic the behavior of a centralized allocator, in a distributed manner.