Table of Contents
Introduction
Amazon Web Services, or AWS, is a large cloud platform that lets you run Linux systems on remote servers instead of your own hardware. As a Linux user, AWS gives you on demand access to virtual machines, storage, and networking that you can control with familiar tools like SSH, the shell, and configuration files. In this chapter you will see what is specific about running Linux on AWS, how a basic setup works, and which AWS services matter most for Linux administration.
Core building blocks: EC2, storage, and networking
On AWS the main service for running Linux is Amazon EC2, which stands for Elastic Compute Cloud. An EC2 instance is a virtual machine that runs on AWS hardware in a specific region and availability zone. For Linux users an EC2 instance behaves like a regular server, you log in with SSH, manage packages, edit configuration files, and run services just as you would on a physical machine.
When you launch an EC2 instance you choose an Amazon Machine Image, or AMI, which defines the base Linux distribution, its initial disk layout, and some default settings. AWS provides official AMIs for distributions such as Amazon Linux, Ubuntu, Debian, Fedora, and others. Many marketplace vendors also provide AMIs with preinstalled software like databases or web stacks. The AMI choice is important because it determines your package manager, directory layout, and default tools.
Every EC2 instance needs storage for its root filesystem. On AWS this is usually an EBS volume, which stands for Elastic Block Store. An EBS volume appears inside the instance as a block device, for example /dev/xvda, and contains filesystems such as EXT4 or XFS. You can attach multiple EBS volumes to the same instance, format them, and mount them where you want, for example as /var/lib/mysql or /data. EC2 instances can also use instance store volumes on some instance types, but these disappear when the instance stops, so persistent data normally stays on EBS.
Networking on EC2 is provided through virtual networks called VPCs, which stands for Virtual Private Cloud. Each instance receives a private IP address inside a VPC subnet. If you want the instance to be reachable from the internet you associate a public IP or an Elastic IP address. For a Linux administrator this means you configure the OS-level network with tools such as ip and the Linux firewall, but you must also understand that many access rules are enforced outside the instance by AWS.
Accessing Linux instances with SSH keys and security groups
A typical first interaction with Linux on AWS is logging in with SSH. AWS uses key based authentication by default instead of passwords. When you create an EC2 instance, you associate it with a key pair. The private key file stays on your local machine, and the public key is stored by AWS and injected into the instance, usually into the ~/.ssh/authorized_keys file of a default user such as ec2-user, ubuntu, or centos, depending on the AMI.
From your machine you connect with an SSH command that looks like:
ssh -i /path/to/private-key.pem ubuntu@your-instance-public-ipOn AWS you also control network access with security groups. A security group is a virtual firewall that applies to one or more instances. You configure which ports are allowed for inbound and outbound traffic. For example, if you want to connect with SSH you must allow TCP port 22. If you host a web server you must allow ports 80 or 443. These permissions are managed in the AWS console or with CLI commands, and they apply before any firewall rules inside the Linux system.
Make sure that SSH access is restricted to trusted IP addresses whenever possible. A security group that allows SSH from all sources, written as 0.0.0.0/0, exposes the instance to constant login attempts from the internet.
Inside the Linux system you can still use tools such as UFW or firewalld to add another layer of protection, but security groups are always evaluated first at the AWS network level.
Using the AWS CLI from Linux
Once you have at least one Linux system running, you can manage AWS itself from the command line by installing the AWS Command Line Interface, often called the AWS CLI. This tool communicates with AWS services through their APIs. From any Linux machine, in the cloud or on your own hardware, you can install the CLI using your distribution package manager or the provided installation script, then configure it with credentials and a default region.
After configuration you can run commands such as aws ec2 describe-instances to list your EC2 instances or aws s3 ls to view S3 buckets. Although there are many AWS services, the CLI format remains broadly consistent, which makes it suitable for automation in shell scripts. Command output is usually JSON, which you can filter with tools such as jq. All of this feels natural for Linux users who already work with pipelines and text processing tools.
From a Linux perspective the important idea is that the AWS CLI is just another command you can run, script, and schedule. This means you can write shell scripts to create backups to S3, rotate snapshots of EBS volumes, or adjust instance settings as part of your system administration tasks.
IAM and permissions from a Linux administrator’s perspective
In AWS you rarely use root account credentials directly. Instead you use IAM, which stands for Identity and Access Management. IAM defines who can perform which actions on AWS resources. Rights are described in policies that allow or deny actions like ec2:StartInstances or s3:PutObject. These policies attach to IAM users, groups, or roles.
For Linux on AWS, IAM roles are particularly important. An IAM role can be attached to an EC2 instance. That instance then automatically receives temporary credentials that your applications and scripts inside Linux can use, for example to access an S3 bucket or publish messages to a queue. This avoids storing long term access keys in configuration files or environment variables.
Inside the Linux environment many tools automatically detect these temporary credentials. The AWS CLI and SDKs look for instance role credentials first, so for scripting you often do not need to hardcode keys. This changes how you think about secrets management compared to traditional Linux servers, because permissions are controlled by AWS outside the instance instead of by local user accounts alone.
Working with S3 from Linux
A common way to store and move data in AWS is S3, which stands for Simple Storage Service. S3 is object storage available over HTTPS, not a traditional Linux filesystem. However, from a Linux system you can treat S3 as a remote location that you interact with using commands instead of mounting it like a local disk.
The aws s3 commands let you list, copy, and synchronize objects. You can upload a file with a command like aws s3 cp file.txt s3://your-bucket/. To sync a local directory to a bucket you use aws s3 sync directory/ s3://your-bucket/. These operations work well for backups or log archival from Linux servers.
There are also tools that expose S3 as a mount point, which allow you to browse it with normal filesystem commands. These tools are convenient, but they often suffer from latency and consistency differences compared to real block storage. For regular Linux administration tasks, streaming data directly with CLI tools is usually more predictable.
Designing Linux instances for the cloud
Running Linux on AWS leads to some design choices that differ from static on premises servers. Instances are often treated as disposable. Configuration is reproducible from templates or scripts, and data persists in services such as EBS, S3, or managed databases. When an instance fails, you replace it rather than repair it in place. This encourages habits like keeping application code in version control and using automated configuration processes.
Load and usage patterns also affect Linux design on AWS. Some workloads run on a single steady instance, but many use multiple instances behind a load balancer or in an auto scaling group. In those setups new Linux instances are started and stopped automatically based on demand. This means local changes that are not captured in your configuration process will disappear. For consistent systems you document and automate everything that matters, rather than relying on manual tuning inside one server.
Networking services such as managed load balancers and managed databases also change the way you integrate services. For example, your Linux web server may accept traffic only from a load balancer within the same VPC, and may connect to a managed database over a private network address. The Linux system sees regular TCP connections, but the lifecycle of the surrounding components is coordinated by AWS.
Monitoring and logging Linux on AWS
Observability is a core part of maintaining Linux in the cloud. On AWS the main service for metrics and logs is CloudWatch. CloudWatch can collect metrics such as CPU usage, network traffic, and disk performance from EC2 instances. It can also accept logs from within the instance, such as application logs or system logs that you choose to forward.
Inside Linux you may configure an agent that reads file logs, for example from /var/log, and sends them to CloudWatch. Once there, you can create alarms that notify you when thresholds are exceeded, such as high CPU or low disk space. For a Linux administrator this is similar to traditional monitoring tools, but integrated directly with the AWS environment.
Since AWS components report their own metrics, you can also correlate what is happening inside Linux with the behavior of surrounding services, such as load balancers or databases. This combined view is one of the main advantages of placing Linux systems inside a cloud environment rather than running them in isolation.
Cost awareness for Linux instances
Running Linux on AWS introduces cost considerations that differ from local hardware. EC2 instances are billed by the time they run. Larger or more capable instances, such as those with more CPU, memory, or specialized hardware, cost more per hour. EBS volumes are billed by size and sometimes by performance tier. Data transfer also has associated costs, especially out of AWS to the public internet.
From a Linux operator’s point of view this affects decisions like instance sizing, whether to keep noncritical instances running all the time, and how often to take and store snapshots. It also influences trade offs when choosing between performing work on a single large instance or many smaller ones. Because everything is programmable, you can automate cost saving behaviors, such as shutting down development instances at night.
Being cost aware does not change most Linux commands you run, but it adds constraints and goals. You may design scheduled tasks that compress logs before moving them to S3, or scripts that delete temporary instances that are no longer in use. Over time this mindset becomes as natural as managing resources like CPU and memory within the operating system itself.
Summary
Linux on AWS combines familiar system administration tasks with a set of cloud specific services that control how your systems start, connect, secure data, and scale. EC2 gives you virtual machines that behave like ordinary Linux servers. EBS, S3, VPC, IAM, and CloudWatch shape how those servers store data, interact with networks, enforce permissions, and report their health. By understanding these components from a Linux point of view you can build systems that are consistent, automatable, and well suited to cloud environments.