随着云计算供应商基础设施的迅速发展，作为云计算的一种服务形式，基础设施既服务（IaaS）系统，得到了日益普及，工具和技术也不断涌现，进而转变为私有云和混合云的基础设施。在这篇论文中将详细介绍OpenNebula和Haizea。

Abstract

More often than not, a “cloud” refers to an “Infrastructure-as-a-Service” (IaaS) cloud, such as Amazon EC2, where IT infrastructure is deployed in a cloud provider’s datacenter in the form of virtual machines. With the growing popularity of IaaS clouds, an ecosystem of tools and technologies is emerging that can transform an organization’s existing infrastructure into a private cloud or a hybrid cloud. In this article, we present OpenNebula, an open source virtual infrastructure manager that can be used to deploy virtualized services on both a local pool of resources and on external IaaS clouds, and Haizea, a resource lease manager that can act as a scheduling backend for OpenNebula providing features not found in other cloud software or virtualization-based datacenter management software, such as advance reservations and resource preemption, which we argue to be specially relevant for private and hybrid clouds.