Cloud Service Models – Infrastructure as a Service(IaaS)
IaaS provides access to fundamental resources such as physical machines, virtual machines, virtual storage etc. Apart from these resource the IaaS also offers:
- Virtual machine disk storage
- Virtual local area network (VLANs)
- Load balancers
- IP addresses
- Software bundles
All of the above resources are made available to end user via server virtualization. Moreover, these resources are accessed by the customers as if they own them.
IaaS allows the cloud provider to freely locate the infrastructure over the internet in cost-effective manner. Some of the key benefits of IaaS are listed below:
- Full Control of the computing resources through Administrative Access to VMs.
- Flexible and Efficient renting of Computer Hardware.
- Portability, Interoperability with Legacy Applications.
FULL CONTROL OVER COMPUTING RESOURCES THROUGH ADMINISTRATIVE ACCESS TO VMS
IaaS allows the consumer to access computing resources through administrative access to virtual machines in the following manner:
- Consumer issues administrative command to cloud provider to run the virtual machine or to save data on cloud’s server.
- Consumer issues administrative command to virtual machines they owned, to start web server or installing new applications.
FLEXIBLE AND EFFICIENT RENTING OF COMPUTER HARDWARE
IaaS resources such as virtual machines, storages, bandwidth, IP addresses, monitoring services, firewalls etc. all are made available to the consumers on rent. The consumer has to pay, based the length of time a consumer retains a resource. Also with administrative access to virtual machines the consumer can also run any software even a custom operating system
PORTABILITY, INTEROPERABILITY WITH LEGACY APPLICATIONS
It is possible to maintain legacy between applications and workloads between IaaS clouds. For example, network applications such as web server, email server that normally runs on consumer-owned server hardware can also be run from VMs in IaaS cloud
IaaS shares issues with PaaS and SaaS, such as Network dependence and browser based risks. It also have some specific issues associated with it. These issues are mentioned in the following diagram:
COMPATIBILITY WITH LEGACY SECURITY VULNERABILITIES
Because IaaS offers the consumer to run legacy software in provider’s infrastructure, therefore, it exposes consumers to all of the security vulnerabilities of such legacy software.
VIRTUAL MACHINE SPRAWL
The VM can become out of date with respect to security updates because IaaS allows the consumer to operate the virtual machines in running, suspended and off state. However, the provider can automatically updates such VMs but this mechanism is hard and complex.
ROBUSTNESS OF VM-LEVEL ISOLATION
IaaS offers an isolated environment to individual consumers through hypervisor. Hypervisor is a software layer that includes hardware support for virtualization to split a physical computer into multiple virtual machines.
DATA ERASE PRACTICES
The consumer uses virtual machines that in turn uses the common disk resources provided by the cloud provider. When the consumer releases the resource, the cloud provider must ensure that next consumer to rent the resource, does not observe data residue from previous consumer.
Here are the characteristics of IaaS service model:
- Virtual machines with pre-installed software.
- Virtual machines with pre-installed Operating Systems such as windows, Linux, and Solaris.
- On-demand availability of resources.
- Allows to store copies of particular data in different locations.
- The computing resources can be easily scaled up and down.