CompTIA Cloud Essentials+ (CLO-002)Management and Technical OperationsMedium
A company is migrating a legacy application to the cloud. The application uses a monolithic architecture and requires a specific operating system and custom runtime libraries that are not readily available as managed services. The development team wants to retain full control over the operating system and application stack. Which cloud service model would be most appropriate for this migration?
- AFunction as a Service (FaaS)
- BInfrastructure as a Service (IaaS)
- CPlatform as a Service (PaaS)
- DSoftware as a Service (SaaS)
Show answer & explanationAnswer & explanation
Correct answer: B. Infrastructure as a Service (IaaS)
IaaS provides virtualized computing resources (VMs, networks, storage) where the user retains full control over the operating system, middleware, and applications, which is essential for legacy applications requiring specific OS and custom libraries.
Why the other options are wrong
- A. FaaS (serverless computing) abstracts all infrastructure, running code in response to events, and is not suitable for monolithic applications needing full OS control.
- C. PaaS provides a development and deployment environment, abstracting the OS and underlying infrastructure, which limits control over custom OS/runtimes.
- D. SaaS provides a complete, ready-to-use application, offering no control over the underlying infrastructure or OS.
Infrastructure as a Service (IaaS)
A cloud service model that provides virtualized computing resources over the internet, including virtual machines, networks, and storage. Users manage the operating systems, applications, and data.
- Highest level of control for the user (OS, runtime, apps).
- Cloud provider manages virtualization, servers, storage, networking.
- Suitable for lift-and-shift migrations of legacy applications.
- Requires more management effort from the user than PaaS or SaaS.
Memory trick: IaaS is for Infrastructure, PaaS for Platform, SaaS for Software.