Who Patches the OS When Databases Run on Amazon EC2?

CLF-C02 By islever Editorial Last updated

Understand the AWS shared responsibility model.

Short answer

C AWS patches the underlying host operating system and hypervisor for EC2, while the customer handles guest OS, database software and backups.

Question

Which responsibility belongs to AWS when a company hosts its databases on Amazon EC2 instances?
  1. Database backups
  2. Database software patches
  3. Operating system patches Correct Answer
  4. Operating system installations

Key Takeaways

It tests the IaaS split of the shared responsibility model — AWS owns the host operating system, virtualization layer and hardware, while the customer owns the guest OS, database engine and data — and the trap is assuming that because the database runs on EC2, AWS also patches the database and its guest OS.

This question tests where the shared responsibility line falls when a database is self-hosted on Amazon EC2 rather than run on a managed service such as Amazon RDS. It establishes that among the listed tasks, operating system patching is the one that sits on the AWS side of the line.

Common mistake: The most common wrong pick is D (operating system installations), on the reasoning that AWS 'provides' the OS through Amazon Machine Images; in the exam model the customer owns everything on the instance from the guest OS upward, so installation and configuration are not AWS tasks.

Expert Analysis

Why the Answer Is Correct

Hosting a database on Amazon EC2 is an IaaS deployment, so the responsibility boundary runs beneath the instance: AWS operates and patches the physical hosts, the virtualization layer and the host operating system that the instance runs on. Of the four tasks listed, operating system patching is the only one that touches that AWS-controlled layer, which is why the exam key points to option C. Everything the customer can log into and change — the guest operating system, the database engine, the data and its backups — stays firmly on the customer's side. Read the option the way the blueprint intends it: the OS layer AWS maintains underneath EC2, not the guest OS you administer. That is the same split AWS describes when it says customers are responsible for "patching the guest operating system" while AWS handles the infrastructure beneath it.

Why the Other Options Are Wrong

Option A, database backups, is unambiguously customer work: AWS supplies snapshot and backup tooling, but designing, scheduling, retaining and testing the backup strategy for a self-managed database is the customer's job. Option B, database software patches, is also customer work — with EC2 you choose and run the engine (MySQL, PostgreSQL, Oracle), so minor-version upgrades and security fixes inside the engine are yours, which is exactly the burden Amazon RDS removes. Option D, operating system installations, is the tempting one, but on EC2 the customer owns the OS that lands on the instance: you pick or build the AMI, bootstrap it, harden it and re-install if needed, so installation is not an AWS responsibility. None of A, B or D can be pushed to AWS without breaking the shared responsibility model.

Community Comment Notes

Dacusai raised the strongest objection, arguing that with EC2 "you are responsible for everything, OS, DB software and patching and back ups" and that no option is truly correct — a fair literal reading, since the customer does patch the guest OS. TheFivePips reached the same conclusion while still selecting D, listing each option as "A. Database backups - Customer responsibility" and then treating OS installation as the exception. MBFK and Direction369 both anchored on IaaS, noting that AWS maintains the "Physical hardware Networking Virtualization" layer, while nani12e434 stated plainly that the AWS-side item is "opearting system patches". The split in the thread shows the real trap: learners correctly recite the IaaS boundary and then apply it to the wrong layer of the operating system.

Official Reference

https://aws.amazon.com/compliance/shared-responsibility-model/

This link opens the official vendor documentation in a new tab.

Exam Strategy

For any EC2-based scenario, draw the line immediately below the guest OS: hardware, virtualization and host OS patching belong to AWS, while everything you can log into or configure belongs to you. Then scan the options for the single task that maps to the infrastructure layer rather than to the instance itself.

Frequently Asked Questions

Why isn't database software patching (option B) an AWS responsibility on EC2?

With EC2 you install and administer the database engine yourself, so version upgrades and security fixes inside that engine are customer tasks. Moving to Amazon RDS shifts engine patching to AWS.

Does moving the database from EC2 to Amazon RDS change which option is correct?

Yes. On RDS, AWS takes over the guest OS and database engine patching, so the customer keeps only data, access and backup-schedule responsibilities.

More CLF-C02 FAQ →

Discussion 36 contributions

Compiled from public community threads and reader submissions, lightly edited for clarity. Handles and vote tallies are shown as recorded, and comments reflect the views of individual contributors.

From public community threads 30 of 36

  1. TheFivePips 👍 6 Answered D
    A. Database backups - Customer responsibility. Customers are responsible for managing and maintaining backups of their data. AWS provides tools and services, but it's up to the customer to implement and manage backup strategies for their databases. B. Database software patches - Customer responsibility. The customer is responsible for applying patches and updates to the database software running on their EC2 instances. This includes managing the software lifecycle, updates, and security patches. C. Operating system patches - Customer responsibility. Similar to database software patches, the customer is responsible for applying patches and updates to the operating system of the EC2 instances. AWS manages the infrastructure, but the customer is responsible for the configuration and maintenance of their instance's operating systems. D. Operating system installations - AWS responsibility. AWS takes care of installing and maintaining the operating system on the EC2 instances. This is part of the underlying infrastructure managed by AWS as a cloud service provider.
  2. Dacusai 👍 4
    When you use an EC2 instance you are responsible for everything, OS, DB software and patching and back ups, AWS only take for the infrastructure that host the EC2 instance. No correct answer here
  3. tqiu654 👍 3 Answered C
    GPT: When a company hosts its databases on Amazon EC2 (Elastic Compute Cloud) instances, the responsibility model followed is the shared responsibility model. In this model, AWS is responsible for the infrastructure layer, while the customer is responsible for the management of the operating system and above, including databases. Among the listed responsibilities: C. Operating system patches: This is the responsibility that belongs to AWS. When using EC2 instances, AWS takes care of the infrastructure layer, which includes the physical hardware, the network, and the facilities that run the AWS Cloud. However, the customer is responsible for managing the operating system installed on the EC2 instances. This includes applying operating system patches.
  4. MBFK 👍 3 Answered C
    The correct answer is: C. Operating system patches Explanation: When a company hosts its databases on Amazon EC2 instances, it falls under the "Infrastructure as a Service" (IaaS) model. AWS is responsible for maintaining the underlying infrastructure, such as: Physical hardware Networking Virtualization However, the management of the EC2 instance itself, including: Installing the operating system Patching the operating system Managing the database software Configuring and backing up the database is the responsibility of the customer. Therefore, AWS handles operating system patches, as it is part of the shared responsibility model related to infrastructure-level management.
  5. Sreeni_A 👍 3
    D is Correct.When a company hosts its databases on Amazon EC2 instances, AWS is responsible for operating system installations. AWS provides and manages the underlying operating system for EC2 instances, ensuring that it is installed and ready for customer use
Show 25 more comments
  1. db97 👍 3 Answered D
    Seems like a tricky one, nonetheless I would go for "D" since its AWS responsibility to prepare/install the OS overall on an instance then the rest is the customer's responsibility.
  2. Jackmann 👍 3 Answered C
    C. Operating system patches ---ChatGPT
  3. Direction369 👍 2 Answered C
    C. Operating system patches The customer is responsible for managing the operating system, including applying patches, while AWS manages the underlying infrastructure. The other options (A, B, and D) are also the customer's responsibility. Operating system patches AWS is responsible for the hypervisor and the physical infrastructure (such as the servers, storage, and networking), but the customer is responsible for managing the operating system and software on their EC2 instances.
  4. rsrjunior 👍 2 Answered D
    D by elimination. on EC2 user is responsible for patching OS. https://aws.amazon.com/compliance/shared-responsibility-model/#:~:text=Patch%20Management%20%E2%80%93%20AWS%20is%20responsible,their%20guest%20OS%20and%20applications. Customers that deploy an Amazon EC2 instance are responsible for management of the guest operating system (including updates and security patches)...
  5. shilpakadiyan 👍 2
    it should be D because customer is responsible for tasks A, B, C as EC2 is infrastructure structure service not managed service So, more operational task would be done by customer itself.
  6. 48f9f03 👍 2
    C is wrong. The customer is responsible for operating-system patches and updates on EC2 Instances, as well as data security on the instances, Security Groups rules, etc.
  7. kdeo 👍 2
    Operating System installation is the customer's responsibility on EC2. How can OS be the answer for this.
  8. evet12 👍 2 Answered D
    AWS is installing OS for you but you are responsible for patching and managing it
  9. dolpaz 👍 2 Answered D
    I think D is correct because AWS is responsible for Installing the OS
  10. bd29 👍 2 Answered D
    D: AWS is only responsible for the initial setup of the instance.
  11. nani12e434 👍 2 Answered C
    aws responsibility - opearting system patches
  12. Dipa_2910 👍 2 Answered C
    Operating system patches
  13. rankocertified 👍 2 Answered D
    by eliminating A,B,C
  14. Mohamedsadat 👍 2 Answered C
    c is correct
  15. tennyson 👍 1
    C. Operating system patches AWS is responsible for the infrastructure, which includes maintaining and patching the underlying hardware and the hypervisor, as well as providing patches and updates for the operating system if the company is using an Amazon-managed AMI (Amazon Machine Image) for the EC2 instance. The customer is responsible for database backups, database software patches, and operating system installations (if they are not using a managed service like Amazon RDS, which handles more of these responsibilities).
  16. santoshchauhan 👍 1 Answered C
    Why the other options are incorrect: A. Database backups: This is the customer's responsibility unless they use a fully managed service like Amazon RDS, which handles backups automatically. B. Database software patches: Customers are responsible for applying patches and updates to the database software running on EC2 instances. D. Operating system installations: Customers are responsible for selecting and installing the operating system on their EC2 instances, even though AWS provides AMIs that can simplify this process.
  17. PcsSdm 👍 1 Answered D
    Copilot The correct answer is: ✅ D. Operating system installations Explanation When a company runs databases on Amazon EC2, AWS follows the Shared Responsibility Model: AWS is responsible for: Physical infrastructure Hardware Networking Hypervisor Providing the EC2 instance and the base AMI (operating system image) The customer is responsible for: Installing and configuring database software Database backups Database software patching Operating system patching and maintenance Data security and access control
  18. 3isthemagicnumber 👍 1 Answered D
    D. AWS provides the infrastructure and services (like EC2) that include a range of Amazon Machine Images (AMIs) with pre-installed operating systems. This means AWS is responsible for ensuring that these AMIs are available and that the underlying infrastructure to run these instances is secure and reliable. The other responsibilities listed - database backups (A), database software patches (B), and operating system patches (C) - are under the purview of the customer when using Amazon EC2 instances.
  19. Mostafa_Shahbakhsh 👍 1 Answered C
    Why not the others? A. Database backups: The customer manages backups for databases hosted on EC2. B. Database software patches: Customers are responsible for patching the database software they install on EC2. D. Operating system installations: Customers choose and install their preferred operating systems on EC2 instances unless they use pre-configured AMIs.
  20. naren_chebolu 👍 1 Answered C
    AWS provides AMIs (Amazon Machine Images) with pre-installed operating systems, but the customer selects and launches the EC2 instance. AWS handles operating system patches as part of its infrastructure management, but customers are responsible for managing and maintaining the databases they host on EC2. Hence, C is the correct answer.
  21. Ruffyit 👍 1
    D. AWS provides the infrastructure and services (like EC2) that include a range of Amazon Machine Images (AMIs) with pre-installed operating systems. This means AWS is responsible for ensuring that these AMIs are available and that the underlying infrastructure to run these instances is secure and reliable.
  22. Amin_013 👍 1 Answered D
    D. Operating system installations - AWS responsibility. AWS takes care of installing and maintaining the operating system on the EC2 instances. This is part of the underlying infrastructure managed by AWS as a cloud service provider.
  23. pgchand 👍 1 Answered D
    the customer is responsible for "security in the cloud," including the guest operating system (OS) patching, database software installation, backups, and data security.
  24. Doaws 👍 1 Answered D
    D. Operating system installations - AWS responsibility. Customer chooses options and AWS automatically install system
  25. discojc 👍 1 Answered D
    When you run a db on EC2 (self managed), AWS provides pre-built AMI's with the OS already installed. So is D

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