To ensure that a cloud infrastructure runs smoothly, the Infrastructure as a Service (IaaS) providers have to manage their physical and virtual resources well. The IaaS providers have to ensure that their servers, networks, storage work alongside holistically and in tandem with physical ones. They should be so well synchronized that the task of resources can be dynamically allocated based on requirements – key feature of cloud computing.

The answer to this problem is – Virtual Infrastructure Manager (VIM). It is a software is responsible for ensuring that physical and virtual resources work smoothly. While it works more or less like a traditional OS but with an exception that it collects resources from many machines at one go. Thus even though multiple machines are used at the backend, applications and even users only see a smooth front end.

Key Features of a Virtual Infrastructure Manager

To make sure cloud operations runs well both at front and backend, a virtual infrastructure manager needs to fulfill some basic requirements / features. Some of them are discussed below:

Supporting the "On Demand" concept of the cloud: The virtual infrastructure manager has most importantly ensurethat the cornerstone of cloud computing – "on demand" and also "self servicing" is provided. Thus users should be able to choose their services and configuration on their own without any human intervention.

Hardware Virtualization: virtualization is one of the most basic and important requirement. Without that it would be impossible to serve multiple front end requirements by a hardware infrastructure. hardware resources such as CPU power and memory will be virtualized and would have to be used based on requirements.

Storage virtualization: The VIM has to abstract logical storage from physical storage. The consolidation of all storage devices of a data center (as used by IaaS providers) and then creation of virtual storage disks ensures multiple storage requirements can be served optimally.

Resource allocation on the fly: Data centers are energy guzzlers. Consolidating them and using fewer machines more efficiently can give significant cost benefits. Most of the virtual infrastructure managers have this dynamic resource allocation feature.

Minimization of downtime: High Availability feature which ensures there is a minimum downtime is very critical for today's businesses.Virtual infrastructure managers use failover mechanism which restart health servers when there is a failure detected.

Data backups: The dependency of data backups on cloud have been skyrocketing. This also means that the IaaS providers themselves to be very careful and proactive in taking backups of their own datacenters to ensure continuity in case of disaster of any other issues.

Popular Virtual Infrastructure Managers

There are many firms which have developed VIMs. Some of the most popular ones along with key features are provided below:

  • VMWare vSphere: This proprietary windows / Linux based VIM by VMWare boasts of almost all features which we have discussed above. One of the primary aims of this VIM is transformation of IT infrastructures into private clouds. This is considered to be a very feature rich VIM primarily because VMWare has multiple offerings in this space
  • Citrix Essentials: This proprietary product is from citrix and works on Windows platform. According to some, this is one of the most complete VIM in terms of features.
  • Enomaly ECP: This GPL v3 licensed VIM is linux based and is developed by Enomaly. According to many experts this is the most complete VIM offering large number of features a IaaS provider needs to build a cloud offering.

Some other prominent VIM names are:

  • AppLogic
  • Eucalyptus
  • OpenPEX
  • Platform VMO
  • Apache VCL
  • Nimbus

It is clear that the role of a Virtual Infrastructure Manager is very critical and important. There are various companies providing VIMs. As an IaaS provider you should evaluate your requirements in terms of features and carefully select the best one. Make sure the VIM selected provides seamless services you have promised to your customers as an IaaS provider.