Launching a virtual machine in the cloud
foundational fluency with cloud compute.
pick image, instance type, network placement and security, attached storage, and access keys.
leaving the instance open to the world or ignoring the security group and key pair.
What's really being asked
This checks baseline cloud literacy. The interviewer wants to confirm you know the knobs that define a VM and that you instinctively think about security and reproducibility.
The full answer
Walk the configuration in order. Start with the machine image, which fixes the operating system and any preinstalled software. Pick an instance type that maps to a CPU, memory, and network profile suited to the workload. Place the instance in a VPC and subnet, deciding whether it needs a public IP, and attach a security group that allows only the ports you intend. Attach block storage, choosing the volume size and performance class, and decide whether the root volume persists on termination. Finally, set up access through an SSH key pair or a cloud identity role, and ideally bake the setup into an image or IaC template so it is repeatable.
The mistakes people make
Forgetting the security group and exposing SSH or RDP to the entire internet. Ignoring whether the subnet is public or private. Embedding long-lived credentials on the box instead of using an instance role. Treating storage as an afterthought.
What usually comes next
How do you connect to a private instance. What is the difference between instance store and persistent block storage. How would you make this launch reproducible. How do you grant the VM permission to call other cloud services.
A concrete example
To run a small web app you select a current Linux image, a general-purpose instance type, and place it in a public subnet with a security group allowing only HTTPS from anywhere and SSH from your office IP. You attach a modest SSD volume, assign an instance role granting read access to a config bucket, and launch with your key pair, capturing the whole setup in a launch template for next time.
Interview question
Which configuration choice most directly controls what network traffic is allowed to reach a newly launched VM?
- a.The instance type and its CPU and memory size
- b.The machine image selected for the operating system
- c.The security group rules attached to the instanceCorrect
- d.The size of the attached block storage volume
Why? this is the answer
Security groups act as a virtual firewall defining permitted inbound and outbound traffic. The image, instance type, and storage size define software and capacity, not network access control.
Just read this? Test yourself on what you have been reading.
Read the original → aws.amazon.com
- #compute
- #virtual-machine
- #ec2
- #fundamentals
- #security-group
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