Cloud computing has become an extremely attractive area of research and practice over the last few years with all the benefits and solutions it provides. Due to security and service level agreement issues of public clouds, the private cloud solution is becoming an appropriate alternative specially with popularity of open source cloud management software that offer a great cost savings in building Infrastructure as a service cloud. However, the increasing number of these software with features vary significantly creates a difficulty for users to choose the software based on their business and scientific requirements. In consequence, the performance evaluation of cloud computing platforms has been receiving a considerable attention as a prominent activity to explore the limitations of cloud solutions and improve service quality, infrastructure planning, and making a wiser selection of the platforms. This thesis focuses on two major goals. The first goal is to design and implement two different private cloud solutions that need to be scalable and completely open source. The clouds are built using the two most popular cloud management platforms, Eucalyptus and CloudStack with different cloud storage configuration. The second goal is to evaluate and compare the architecture, features and performance of the deployed clouds thoroughly to assess its suitability to be adopted as a private cloud solution for different users' purposes. This goal is achieved by first, carrying out a comparative study between the clouds platforms using a set of evaluation criteria which are developed for this purpose. Second, evaluating the performance of virtual machines created by Eucalyptus and CloudStack clouds in terms of CPU utilization, memory bandwidth, disk I/O speed, and network performance. The performance of virtual machines has been compared with regard to bare-metal or traditional infrastructure. Finally cloud management operations such as provisioning time and live migration of virtual machines are assessed considering different related metrics. As a further performance testing, a web application has been implemented on both clouds to evaluate their suitability in web applications hosting. The results show that cloud computing is prepared to replace the traditional infrastructure and successfully hosts most typical web applications. It has been found that storage configuration of the cloud largely affects virtual machines performance. The choice between platforms and storage configuration requires a careful study especially with intensive resource applications. It has been found that CloudStack is more suitable in hosting web applications and for providing cloud services in general due to its scalability, stability and fair virtual machine performance. The Eucalyptus is easier in deployment and more modular where components may be replaced or enhanced in order to foster future cloud research efforts or in testing a specific application on the cloud so it’s a good choice for developers and researchers in this field.