In a stand-alone hardware infrastructure, adding an extra memory or CPU to a hardware unit may take 3-5 months time involving various members following various internal processes like purchase request, infrastructure internal process, service provider internal purchase process and etc. The longer lead time and more involvement from various teams are required because of current enterprise hardware design. Most of  IT organization has more stand-alone servers and it limits the flexibility to add additional resources to the servers.
Due to above reasons, during the initiation phase of any project, the lenient hardware capability planning is done.  It is not ideal nor cost efficient.  This problem can be solved by procuring a bigger server and partition it as need arises. The concept has been in use in mainframe platform for last three decades and each partition in mainframe is called LPAR (Logical PARtition). The similar concept proliferated in the Unix world and major Unix operating systems AIX, Sun Solaris and HP-UX supports it now.
Operating systems Aix, Sun Solaris, and HP-UX run on their host RISC processors from IBM, Sun, and HP respectively.  RISC processor are designed for high volume high speed processing  there is a perception within IT leadership team including  CIOs that only the RISC processors are suitable for data center operations.    The cost of virtualization operating system and blade chassis hardware for RISC based server farm are more expensive than CISC (Complex Instruction Set Computer)processor (like Intel Xeon, AMD) based server farms.  CISC processor based servers had the perception that it is meant for a small scale business and not ready for enterprise data center operation.  It has been a challenge to enterprise architects and IT strategist to convince the IT leadership team to re-platform the existing expensive and inflexible stand alone RISC based servers.

Popularity, acceptance, and adoption of social networking platforms like web 2.0 indirectly helped IT leadership team to rethink about their perception on the CISC based servers for data center operations.  The popular social network sites like facebook runs on Linux platform and the number of users in social networking sites exponentially growing.  It is empirical proof that CISC processor based server are ready for high volume and high-speed data center operations.

With current economic climate, IT leadership team in all sectors have the following objectives.

• Reduce infrastructure cost (Capital Expense, CAPEX)
• Reduce over all data center operation cost  (Operational Expense, OPEX)
• Utilize more energy-efficient (for both Green and cost purpose) devices
• Minimize lost revenue due to down time

The above objective can be met by developing a cost-effective private cloud. It will additionally provide more flexibility and enable the organization to become  more nimble and agile.

How to architect the private cloud?

First and fore most, cloud operating system is required to manage a set of hardware to virtualize it to create virtual image.  There are two types of cloud operating system available.

1. Hosted Server cloud operating system
2. Bare-metal server cloud operating system

1. Hosted server cloud operating system requires a host operating system. The cloud operating system runs on top of the host operating system. The devices are directly managed by the host operating system. It is not designed to clone the operating system and create an image. It is primarly dessigned to clone an application. It is not recommended to run the data center operation like data ware house.

2. Bare-metal server cloud operating system has a micro kernel to manage all hardware directly. Generally the micro kernel is developed very effectively. There are open source cloud operating system available. If you are running mission critical  system, it is highly recommended to run under the commercial cloud operating system. VmWare ESX Server is one of the popular commercial cloud operating system. The micro kernel of VmWare ESX  written very effectively and does a great job of managing the resources.

What are the hardware requirements for private cloud?Well, it depends. There are quite a few certified hardware providers supply servers to  run under VmWare ESX Server. All major manufacturers like Dell, HP, IBM, Fujitsu hardware both blade and racks runs under VmWare ESX Server.  Similarly major manufacturers in storage area network, SCSI controllers, RAID controllers, Fiber Channel adapters, Ethernet Nic support VmWare ESX. Select the hardware, memory and storage based on your needs. There are guidelines available to select the hardware units. Those guidelines will be followed based on the need.

What are the target operating systems ?Well, again, it depends on the requirement. It supports both Linux and Windows. It support all major flavor of Linux (like Redhat, Novel SuSE) and Windows server platform. VmWare ESX can support both operating system at the same time.  The size of the image can be selected based on the requirement.

Results

With the private cloud architecture using Intel/AMD processors, all the above objectives are being met.