At IaaS , short for Infrastracture as a Service , is a service model of cloud technologies. The user can manage the environment himself, apart from the physical infrastructure. IaaS also offers the advantage that it is comparatively inexpensive by sharing resources with other users. In addition, this service model is structured in such a way that several servers are provided in a network in a data center, which together form a cloud. In other words, the hardware is virtualized and thus enables companies to keep their financial expenses in the cloud area low.

Packages from IaaS

The resources linked to this system are usually made available in a kind of smaller package. These in turn contain individual components such as:

  • Virtual CPUs: Virtual CPUs differ from real CPUs in that no dedicated CPUs are provided for a customer, but the calculations are carried out on currently “free” cores.
  • Storage: Typically there is a choice between HDD (optimized for low costs and few accesses) and SSD (optimized for fast and many accesses).
  • Network: Own networks can be created and incoming and outgoing firewall rules can be defined.
  • operating system (English Operating System – OS): Usually you have the choice between Linux and Windows Server. Linux (including CentOS, Ubuntu and Debian) is the most common.

Advantages and disadvantages

At the same time, as with any other system, this service model also has significant advantages and disadvantages. At IaaS, these are broken down as follows:


  • Greatest flexibility compared to other service models
  • Easily portable thanks to the VMs offered
  • Provision of VM and operating system
  • Possibility of adapting the environment at any time
  • Flexible and individual requirements can be implemented at any time

On the other hand, there are also some negative aspects:


  • High effort, e.g. when scaling
  • Increase in performance (e.g. with an increasing user base) must be adjusted yourself, as well as additional tasks in the area of setting up B. Load balancers, monitoring and distributed storage


In addition, IaaS consists of a number of different components. Which is why I analyzed the most important ones in more detail below.

VM (virtual machines / server)

The abbreviation VM stands for the term virtual machine and describes the fundamental element on which the cloud is based. It reflects the software representation of a normal computer with operating system, access to virtual CPUs, RAM, data, etc. The VM thus solves the problem of the need for an additional computer if an additional operating system is required. With the help of software (hypervisor) that is responsible for coordination, any number of virtual computers can run on one computer.


With Storage the solutions for storing the permanent backup of digital data in IT are described. It is up to you whether the storage is made up of hard drives or other technologies such as USB sticks.

In general, a distinction is made between three different types of storage:

  • Direct Attached Storage (DAS) : Single hard drive attached to the server
  • Network Attached Storage (NAS): Hard disk storage with network connection (network of hard disks)
  • Storage Area Network (SAN): Network for the connection of hard disk subsystems (connection of several storage devices with a file server)

Network access

The use of a virtual machine (VM) usually requires an IT expert who not only connects to it, but can also secure the VM against unauthorized access. Such access can also take place in many different ways, with SSH and VPN being the most common solutions.

  • SSH (Secure Shell): Network protocol with encrypted access by IT experts, e.g. in the form of a password and mutual authentication using certificates with secure key procedures.
  • VPN (Virtual Private Network): Use can only be made by certain participants and communication can only take place via its own, specially secured VPN protocol with data encryption.

Network security and monitoring

In addition, the VM must also be protected against unwanted access via the Internet by means of a secure firewall, so that data packets can safely enter and exit.

In addition, there should also be a monitoring solution that regularly checks the performance of the VM and, if necessary, should also sound an alarm, such as failures.

operating system

A suitable operating system is selected along with the virtual machine (VM). The following systems are frequently selected:

CentOS (Community Enterprise Operating System)

  • Developed by RedHat
  • Open source solution
  • Conclusion: free distribution, based on RedHat Enterprise Linux (RHEL)

Ubuntu (German: “Humanity)

  • Based on Debian
  • most used system on private Linux PCs
  • Open source solution
  • Conclusion: easy to install and easy to use, lots of tutorials


  • Based on Linux
  • Open source solution
  • Conclusion: fewer interfaces with simple clicks, more for experienced users


  • Probably the best known operating system
  • Conclusion: Particularly suitable in conjunction with Microsoft solutions, many different versions available


The bottom line is that IaaS is often the first entry into the field of cloud technologies. Relatively easy to use, you basically only have to rent a virtual server here. This must then be equipped with network components and a firewall as well as an operating system and storage solutions. Ultimately, all you have to do is set up the server individually to suit your needs.

Tip: Read my new book: The way to the cloud at Springer Gabler or book me for a talk .


Lindner, D., Niebler, P., & Wenzel, M. (2020). The way to the cloud – a guide for entrepreneurs and decision-makers . Heidelberg: Springer Gabler.


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I blog about the influence of digitalization on our working world. For this purpose, I provide content from science in a practical way and show helpful tips from my everyday professional life. I am an executive in an SME and I wrote my doctoral thesis at the University of Erlangen-Nuremberg at the Chair of IT Management.

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