Resumen
In the datacenter rented to Internet Service Providers (ISPs), the low utilization of racks can seriously affect ISPs? benefit because the ISPs are charged by ?rack per year? rather than servers. Based on our analysis about the utilization data from production systems, we find that the over-provisioning of power results in low power utilization, which potentially decreases rack utilization as well as the ISPs? benefit. To improve the rack utilization, maximizing the number of servers in racks is an effective way. In this paper, we propose a server placement algorithm to minimize the power fragment in a rack. The experimental results show that it can save more than 50% leasing cost (rack utilization improvement) in evaluation.