A Game of Stacks : OpenStack vs. CloudStack

February 8, 2014

Several organizations are now investing in cloud computing because they have realized it has the ability to promote rapid growth while at the same time reducing the speed and costs of application deployment. Enterprises no longer need to carry the heavy burden of maintaining computing resources that are used periodically and left idle most of […]

Several organizations are now investing in cloud computing because they have realized it has the ability to promote rapid growth while at the same time reducing the speed and costs of application deployment. Enterprises no longer need to carry the heavy burden of maintaining computing resources that are used periodically and left idle most of the time. However; even as the hype around cloud computing continues to grow, there are still numerous cloud related issues that are the source of debate and controversy, especially on the enterprise level. A good example is the CloudStack vs. OpenStack debate.

Open source is usually praised amongst IT professionals mainly because it provides an IT environment with a large community of support. Consumers also love it because it frees them from licensing costs while providing both flexibility and customization. When it comes to open source Infrastructure as a service (IaaS) there are two key players; OpenStack and CloudStack.

Both CloudStack and OpenStack are open source software platforms for IaaS that offer cloud orchestration architectures used to make the management of cloud computing easier and more efficient. This open source cloud squabble began when Citrix, a former OpenStack supporter, announced that it was going to re-establish its own cloud stack  under the Apache foundation. The ensuing battle between the two is of a strategic nature with both trying to become the open source IaaS stack most used for building enterprise private clouds.

One thing remains certain, open source cloud platforms are popular for the same reasons Linux took hold; low cost point of entry and the prospect of application portability. The only way to gauge which cloud stack platform is likely to win this game of stacks, is to take a closer look at both.





CloudStack is quickly gaining momentum amongst several organizations. Initially developed by Cloud.com, CloudStack was purchased by Citrix then later on released into the Apache Incubator program. It is now governed by the Apache Software Foundation and supported by Citrix. Since the Apache transition, other vendors have also joined the effort by enhancing and adding core capabilities to the core software. The first stable version of CloudStack was released in 2013.

The Good 

  1. Unique Features: The latest version of CloudStack includes commendable features such as storage independent compute and new security features that enable admins to create security zones across different regions. Its features enable day-to-day use and resource availability.
  2. Smooth Deployment: The installation Of CloudStack is quite streamlined. In a normal setup, only one VM would run the CloudStack management server while another VM acts as the de facto cloud infrastructure. From a deployment and testing perspective, the whole platform can be deployed on one physical host.
  3. Scalability: CloudStack has been designed for centralized management and massive scalability; enabling the effective management of numerous geographically distributed servers from a single portal.
  4. Multi Hypervisor support: The CloudStack software supports multiple hypervisors, including Citrix XenServer, Oracle VM, VMware,  KVM and vSphere. On top of that, CloudStack also supports a variety of networking models, like flat networks, VLANs and openflow.
  5. Detailed Documentation: The CloudStack documentation is well structured and one can easily follow it and eventually get something that works.
  6. Interactive Web UI: CloudStack has a polished and advanced web interface that makes it more user friendly.

The Bad

  1. Rigid Installation process and Architecture: CloudStack’s monolithic architecture has posed some challenges one of them being reduced installation flexibility. In some cases, additional knowledge might be required to install it.

The Ugly

  1. Community Support: Since CloudStack is relatively new in the open source IaaS space, it lacks a large community support base and it is not backed as much from the industry. However, this is likely to change considering the fact that CloudStack comes with a refined product coupled with a heavy user adoption.



OpenStack is an open source IaaS initiative for managing and creating huge groups of virtual private servers in a cloud computing environment. It was initially developed by Rackspace and NASA. With an upwards of 200 companies adopting this platform, it is definitely one of the most popular cloud models out there. OpenStack’s main goal is to support interoperability between cloud services while enabling enterprises to create Amazon-like cloud services within their own data centers.

It is currently under the management of the OpenStack Foundation and is freely available under the Apache 2.0 license. OpenStack consists of a variety of interrelated stack parts that are all tired together to create the OpenStack delivery model.  The popularity of OpenStack has earned it the title of “the Linux of the cloud”

The Good

  1. Hypervisor support: Open Stack provides support for Xen and KVM, with limited support for  VMware ESX, Citrix Xen server and Microsoft Hyper-V. It does not support bare-metal servers and Oracle VM.
  2. Wide integration with storage and Compute technologies:  Constant storage is provided using OpenStack object storage to manage the local disk on compute node clusters. A variety of machine image types such as OVF, VMDK,VDI,VHD, and Raw are managed via the OpenStack image service.
  3. Enhanced Networking Capabilities:  OpenStack has a networking component (Neutron) that has direct integration with OpenFlow and allows higher levels of cloud scaling and multi-tenancy by adopting a variety of software-defined networking technologies into the cloud. Additionally, the OpenStack networking framework contains services like load-balancing features, intrusion detection services (IDS) and firewall technologies. All these features make OpenStack a stack platform capable of great failover and resilience.
  4. Large Community Support: OpenStack is without doubt the most mature stack-based cloud control model. It has the backing of large industry players like Dell, HP, and IBM alongside a long list of contributors.

The Bad

  1. Difficult to Configure and deploy: Since OpenStack is deployed through specific important incubator projects; expertise and time is required to get it up and running. Admins have said that several key components have to be managed from different command line consoles. OpenStack has eight modular components – Image server, Identity service, Dashboard, Networking, Block storage, Open storage, Amazon Web Services and compute compatibility. To some, this encompasses a slightly fragmented architecture; however, the upside of having several modular components is that users can choose which features/projects are required.

The Ugly

  1. Not Enterprise ready: One of the major downsides of OpenStack is the fact that it has not been packaged for enterprise; however, the situation is likely to change considering its large number of contributors.

Author: Gabriel Lando

By Team FileCloud