dataset/docs/ec2.txt

Amazon Elastic Compute Cloud

User Guide

What is Amazon EC2?
Amazon Elastic Compute Cloud (Amazon EC2) provides on-demand, scalable computing capacity
in the Amazon Web Services (AWS) Cloud. Using Amazon EC2 reduces hardware costs so you can
develop and deploy applications faster. You can use Amazon EC2 to launch as many or as few
virtual servers as you need, configure security and networking, and manage storage. You can add
capacity (scale up) to handle compute-heavy tasks, such as monthly or yearly processes, or spikes in
website traffic. When usage decreases, you can reduce capacity (scale down) again.
An EC2 instance is a virtual server in the AWS Cloud. When you launch an EC2 instance, the
instance type that you specify determines the hardware available to your instance. Each instance
type offers a different balance of compute, memory, network, and storage resources. For more
information, see the Amazon EC2 Instance Types Guide.

Features of Amazon EC2
Amazon EC2 provides the following high-level features:
Instances
Virtual servers.
Amazon Machine Images (AMIs)
Preconfigured templates for your instances that package the components you need for your
server (including the operating system and additional software).
Instance types
Various configurations of CPU, memory, storage, networking capacity, and graphics hardware
for your instances.
Features

1

Amazon Elastic Compute Cloud

User Guide

Amazon EBS volumes
Persistent storage volumes for your data using Amazon Elastic Block Store (Amazon EBS).
Instance store volumes
Storage volumes for temporary data that is deleted when you stop, hibernate, or terminate
your instance.
Key pairs
Secure login information for your instances. AWS stores the public key and you store the private
key in a secure place.
Security groups
A virtual firewall that allows you to specify the protocols, ports, and source IP ranges that can
reach your instances, and the destination IP ranges to which your instances can connect.
Amazon EC2 supports the processing, storage, and transmission of credit card data by a merchant
or service provider, and has been validated as being compliant with Payment Card Industry (PCI)
Data Security Standard (DSS). For more information about PCI DSS, including how to request a
copy of the AWS PCI Compliance Package, see PCI DSS Level 1.

Related services
Services to use with Amazon EC2
You can use other AWS services with the instances that you deploy using Amazon EC2.
Amazon EC2 Auto Scaling
Helps ensure you have the correct number of Amazon EC2 instances available to handle the
load for your application.
AWS Backup
Automate backing up your Amazon EC2 instances and the Amazon EBS volumes attached to
them.
Amazon CloudWatch
Monitor your instances and Amazon EBS volumes.
Related services

2

Amazon Elastic Compute Cloud

User Guide

Access Amazon EC2
You can create and manage your Amazon EC2 instances using the following interfaces:
Amazon EC2 console
A simple web interface to create and manage Amazon EC2 instances and resources. If you've
signed up for an AWS account, you can access the Amazon EC2 console by signing into the AWS
Management Console and selecting EC2 from the console home page.
AWS Command Line Interface
Enables you to interact with AWS services using commands in your command-line shell. It is
supported on Windows, Mac, and Linux. For more information about the AWS CLI , see AWS
Command Line Interface User Guide. You can find the Amazon EC2 commands in the AWS CLI
Command Reference.
AWS CloudFormation
Amazon EC2 supports creating resources using AWS CloudFormation. You create a template, in
JSON or YAML format, that describes your AWS resources, and AWS CloudFormation provisions
and configures those resources for you. You can reuse your CloudFormation templates to
provision the same resources multiple times, whether in the same Region and account or in
multiple Regions and accounts. For more information about supported resource types and
properties for Amazon EC2, see EC2 resource type reference in the AWS CloudFormation User
Guide.
AWS SDKs
If you prefer to build applications using language-specific APIs instead of submitting a request
over HTTP or HTTPS, AWS provides libraries, sample code, tutorials, and other resources
for software developers. These libraries provide basic functions that automate tasks such
as cryptographically signing your requests, retrying requests, and handling error responses,
making it easier for you to get started. For more information, see Tools to Build on AWS.
AWS Tools for PowerShell
A set of PowerShell modules that are built on the functionality exposed by the SDK for .NET.
The Tools for PowerShell enable you to script operations on your AWS resources from the
PowerShell command line. To get started, see the AWS Tools for PowerShell User Guide. You
can find the cmdlets for Amazon EC2, in the AWS Tools for PowerShell Cmdlet Reference.
Access EC2

4

Amazon Elastic Compute Cloud

User Guide

Get started with Amazon EC2
Use this tutorial to get started with Amazon Elastic Compute Cloud (Amazon EC2). You'll learn how
to launch and connect to an EC2 instance. An instance is a virtual server in the AWS Cloud. With
Amazon EC2, you can set up and configure the operating system and applications that run on your
instance.
Overview
The following diagram shows the key components that you'll use in this tutorial:
• An image – A template that contains the software to run on your instance, such as the operating
system.
• A key pair – A set of security credentials that you use to prove your identity when connecting to
your instance. The public key is on your instance and the private key is on your computer.
• A network – A virtual private cloud (VPC) is a virtual network dedicated to your AWS account.
To help you get started quickly, your account comes with a default VPC in each AWS Region, and
each default VPC has a default subnet in each Availability Zone.
• A security group – Acts as a virtual firewall to control inbound and outbound traffic.
• An EBS volume – We require a root volume for the image. You can optionally add data volumes.

8

Amazon Elastic Compute Cloud

User Guide

Cost for this tutorial
When you create your AWS account, you can get started with Amazon EC2 for free using the AWS
Free Tier.
If you created your AWS account before July 15, 2025, it's less than 12 months old, and you haven't
already exceeded the Free Tier benefits for Amazon EC2, it won't cost you anything to complete
this tutorial, because we help you select options that are within the Free Tier benefits. Otherwise,
you'll incur the standard Amazon EC2 usage fees from the time that you launch the instance (even
if it remains idle) until you terminate it.
If you created your AWS account on or after July 15, 2025, it's less than 6 months old, and you
haven't used up all your credits, it won't cost you anything to complete this tutorial, because we
help you select options that are within the Free Tier benefits.
For information on how to determine whether you are eligible for the Free Tier, see the section
called “Track your Free Tier usage”.
Tasks
• Step 1: Launch an instance
• Step 2: Connect to your instance
• Step 3: Clean up your instance
9

Amazon Elastic Compute Cloud

User Guide

• Next steps

Step 1: Launch an instance
You can launch an EC2 instance using the AWS Management Console as described in the following
procedure. This tutorial is intended to help you quickly launch your first instance, so it doesn't
cover all possible options.
To launch an instance
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

2.

In the navigation bar at the top of the screen, we display the current AWS Region — for
example, Ohio. You can use the selected Region, or optionally select a Region that is closer to
you.

3.

From the EC2 console dashboard, in the Launch instance pane, choose Launch instance.

4.

Under Name and tags, for Name, enter a descriptive name for your instance.

5.

Under Application and OS Images (Amazon Machine Image), do the following:
a.

Choose Quick Start, and then choose the operating system (OS) for your instance. For
your first Linux instance, we recommend that you choose Amazon Linux.

b.

From Amazon Machine Image (AMI), select an AMI that is marked Free Tier eligible.

6.

Under Instance type, for Instance type, select an instance type that is marked Free Tier
eligible.

7.

Under Key pair (login), for Key pair name, choose an existing key pair or choose Create new
key pair to create your first key pair.

Warning
If you choose Proceed without a key pair (Not recommended), you won't be able to
connect to your instance using the methods described in this tutorial.
8.

Under Network settings, notice that we selected your default VPC, selected the option to use
the default subnet in an Availability Zone that we choose for you, and configured a security
group with a rule that allows connections to your instance from anywhere (0.0.0.0.0/0).

Step 1: Launch an instance

10

Amazon Elastic Compute Cloud

User Guide

Warning
If you specify 0.0.0.0/0, you are enabling traffic from any IP addresses in the world.
For the SSH and RDP protocols, you might consider this acceptable for a short time
in a test environment, but it's unsafe for production environments. In production, be
sure to authorize access only from the appropriate individual IP address or range of
addresses.

For your first instance, we recommend that you use the default settings. Otherwise, you can
update your network settings as follows:

9.

•

(Optional) To use a specific default subnet, choose Edit and then choose a subnet.

•

(Optional) To use a different VPC, choose Edit and then choose an existing VPC. If the VPC
isn't configured for public internet access, you won't be able to connect to your instance.

•

(Optional) To restrict inbound connection traffic to a specific network, choose Custom
instead of Anywhere, and enter the CIDR block for your network.

•

(Optional) To use a different security group, choose Select existing security group and
choose an existing security group. If the security group does not have a rule that allows
connection traffic from your network, you won't be able to connect to your instance. For
a Linux instance, you must allow SSH traffic. For a Windows instance, you must allow RDP
traffic.

Under Configure storage, notice that we configured a root volume but no data volumes. This
is sufficient for test purposes.

10. Review a summary of your instance configuration in the Summary panel, and when you're
ready, choose Launch instance.
11. If the launch is successful, choose the ID of the instance from the Success notification to open
the Instances page and monitor the status of the launch.
12. Select the checkbox for the instance. The initial instance state is pending. After the instance
starts, its state changes to running. Choose the Status and alarms tab. After your instance
passes its status checks, it is ready to receive connection requests.

Step 1: Launch an instance

11

Amazon Elastic Compute Cloud

User Guide

Step 2: Connect to your instance
The procedure that you use depends on the operating system of the instance. If you can't connect
to your instance, see Troubleshoot issues connecting to your Amazon EC2 Linux instance for
assistance.

Linux instances
You can connect to your Linux instance using any SSH client. If you are running Windows on
your computer, open a terminal and run the ssh command to verify that you have an SSH client
installed. If the command is not found, install OpenSSH for Windows.
To connect to your instance using SSH
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

2.

In the navigation pane, choose Instances.

3.

Select the instance and then choose Connect.

4.

On the Connect to instance page, choose the SSH client tab.

5.

(Optional) If you created a key pair when you launched the instance and downloaded the
private key (.pem file) to a computer running Linux or macOS, run the example chmod
command to set the permissions for your private key.

6.

Copy the example SSH command. The following is an example, where key-pair-name.pem
is the name of your private key file, ec2-user is the username associated with the image, and
the string after the @ symbol is the public DNS name of the instance.
ssh -i key-pair-name.pem ec2-user@ec2-198-51-100-1.us-east-2.compute.amazonaws.com

7.

In a terminal window on your computer, run the ssh command that you saved in the previous
step. If the private key file is not in the current directory, you must specify the fully-qualified
path to the key file in this command.
The following is an example response:
The authenticity of host 'ec2-198-51-100-1.us-east-2.compute.amazonaws.com
(198-51-100-1)' can't be established.
ECDSA key fingerprint is l4UB/neBad9tvkgJf1QZWxheQmR59WgrgzEimCG6kZY.
Are you sure you want to continue connecting (yes/no)?

Step 2: Connect to your instance

12

Amazon Elastic Compute Cloud

8.

User Guide

(Optional) Verify that the fingerprint in the security alert matches the instance fingerprint
contained in the console output when you first start an instance. To get the console output,
choose Actions, Monitor and troubleshoot, Get system log. If the fingerprints don't match,
someone might be attempting a man-in-the-middle attack. If they match, continue to the next
step.

9.

Enter yes.
The following is an example response:
Warning: Permanently added 'ec2-198-51-100-1.useast-2.compute.amazonaws.com' (ECDSA) to the list of known hosts.

Windows instances
To connect to a Windows instance using RDP, you must retrieve the initial administrator password
and then enter this password when you connect to your instance. It takes a few minutes after
instance launch before this password is available. Your account must have permission to call the
GetPasswordData action. For more information, see Example policies to control access the Amazon
EC2 API.
The default username for the Administrator account depends on the language of the operating
system (OS) contained in the AMI. To determine the correct username, identify the language
of the OS, and then choose the corresponding username. For example, for an English OS, the
username is Administrator, for a French OS it's Administrateur, and for a Portuguese OS it's
Administrador. If a language version of the OS does not have a username in the same language,
choose the username Administrator (Other). For more information, see Localized Names for
Administrator Account in Windows in the Microsoft website.
To retrieve the initial administrator password
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

2.

In the navigation pane, choose Instances.

3.

Select the instance and then choose Connect.

4.

On the Connect to instance page, choose the RDP client tab.

5.

For Username, choose the default username for the Administrator account. The username you
choose must match the language of the operating system (OS) contained in the AMI that you

Step 2: Connect to your instance

13

Amazon Elastic Compute Cloud

User Guide

used to launch your instance. If there is no username in the same language as your OS, choose
Administrator (Other).
6.

Choose Get password.

7.

On the Get Windows password page, do the following:
a.

Choose Upload private key file and navigate to the private key (.pem) file that you
specified when you launched the instance. Select the file and choose Open to copy the
entire contents of the file to this window.

b.

Choose Decrypt password. The Get Windows password page closes, and the default
administrator password for the instance appears under Password, replacing the Get
password link shown previously.

c.

Copy the password and save it in a safe place. This password is required to connect to the
instance.

The following procedure uses the Remote Desktop Connection client for Windows (MSTSC). If
you're using a different RDP client, download the RDP file and then see the documentation for the
RDP client for the steps to establish the RDP connection.
To connect to a Windows instance using an RDP client
1.

On the Connect to instance page, choose Download remote desktop file. When the
file download is finished, choose Cancel to return to the Instances page. The RDP file is
downloaded to your Downloads folder.

2.

Run mstsc.exe to open the RDP client.

3.

Expand Show options, choose Open, and select the .rdp file from your Downloads folder.

4.

By default, Computer is the public IPv4 DNS name of the instance and User name is the
administrator account. To connect to the instance using IPv6 instead, replace the public IPv4
DNS name of the instance with its IPv6 address. Review the default settings and change them
as needed.

5.

Choose Connect. If you receive a warning that the publisher of the remote connection is
unknown, choose Connect to continue.

6.

Enter the password that you saved previously, and then choose OK.

7.

Due to the nature of self-signed certificates, you might get a warning that the security
certificate could not be authenticated. Do one of the following:
•

If you trust the certificate, choose Yes to connect to your instance.

Step 2: Connect to your instance

14

Amazon Elastic Compute Cloud

•

User Guide

[Windows] Before you proceed, compare the thumbprint of the certificate with the value
in the system log to confirm the identity of the remote computer. Choose View certificate
and then choose Thumbprint from the Details tab. Compare this value to the value of
RDPCERTIFICATE-THUMBPRINT in Actions, Monitor and troubleshoot, Get system log.

•

[Mac OS X] Before you proceed, compare the fingerprint of the certificate with the
value in the system log to confirm the identity of the remote computer. Choose Show
Certificate, expand Details, and choose SHA1 Fingerprints. Compare this value to the
value of RDPCERTIFICATE-THUMBPRINT in Actions, Monitor and troubleshoot, Get
system log.

8.

If the RDP connection is successful, the RDP client displays the Windows login screen and
then the Windows desktop. If you receive an error message instead, see the section called
“Remote Desktop can't connect to the remote computer”. When you are finished with the RDP
connection, you can close the RDP client.

Step 3: Clean up your instance
After you've finished with the instance that you created for this tutorial, you should clean up by
terminating the instance. If you want to do more with this instance before you clean up, see Next
steps.

Important
Terminating an instance effectively deletes it; you can't reconnect to an instance after
you've terminated it.

You'll stop incurring charges for that instance or usage that counts against your Free Tier limits as
soon as the instance status changes to shutting down or terminated. To keep your instance
for later, but not incur charges or usage that counts against your Free Tier limits, you can stop the
instance now and then start it again later. For more information, see Stop and start Amazon EC2
instances.
To terminate your instance
1.

In the navigation pane, choose Instances. In the list of instances, select the instance.

2.

Choose Instance state, Terminate (delete) instance.

Step 3: Clean up your instance

15

Amazon Elastic Compute Cloud

3.

User Guide

Choose Terminate (delete) when prompted for confirmation.
Amazon EC2 shuts down and terminates your instance. After your instance is terminated, it
remains visible on the console for a short while, and then the entry is automatically deleted.
You cannot remove the terminated instance from the console display yourself.

Next steps
After you start your instance, you might want to explore the following next steps:
• Explore the Amazon EC2 core concepts with the introductory tutorials. For more information, see
Tutorials for launching EC2 instances.
• Learn how to track your Amazon EC2 Free Tier usage using the console. For more information,
see the section called “Track your Free Tier usage”.
• Configure a CloudWatch alarm to notify you if your usage exceeds the Free Tier (for accounts
created before July 15, 2025). For more information, see Tracking your AWS Free Tier usage in
the AWS Billing User Guide.
• Add an EBS volume. For more information, see Create an Amazon EBS volume in the Amazon EBS
User Guide.
• Learn how to remotely manage your EC2 instance using the Run command. For more
information, see AWS Systems Manager Run Command in the AWS Systems Manager User Guide.
• Learn about instance purchasing options. For more information, see Amazon EC2 billing and
purchasing options.
• Get advice about instance types. For more information, see Get recommendations from EC2
instance type finder.

Next steps

16

Amazon Elastic Compute Cloud

User Guide

Best practices for Amazon EC2
To ensure the maximum benefit from Amazon EC2, we recommend that you perform the following
best practices.
Security
• Manage access to AWS resources and APIs using identity federation with an identity provider and
IAM roles whenever possible. For more information, see Creating IAM policies in the IAM User
Guide.
• Implement the least permissive rules for your security group.
• Regularly patch, update, and secure the operating system and applications on your instance.
For more information, see Update management. For guidelines specific to Windows operating
systems, see Security best practices for Windows instances.
• Use Amazon Inspector to automatically discover and scan Amazon EC2 instances for software
vulnerabilities and unintended network exposure. For more information, see the Amazon
Inspector User Guide.
• Use AWS Security Hub controls to monitor your Amazon EC2 resources against security best
practices and security standards. For more information about using Security Hub, see Amazon
Elastic Compute Cloud controls in the AWS Security Hub User Guide.
Storage
• Understand the implications of the root device type for data persistence, backup, and recovery.
For more information, see Root device type.
• Use separate Amazon EBS volumes for the operating system versus your data. Ensure that the
volume with your data persists after instance termination. For more information, see Preserve
data when an instance is terminated.
• Use the instance store available for your instance to store temporary data. Remember that the
data stored in instance store is deleted when you stop, hibernate, or terminate your instance.
If you use instance store for database storage, ensure that you have a cluster with a replication
factor that ensures fault tolerance.
• Encrypt EBS volumes and snapshots. For more information, see Amazon EBS encryption in the
Amazon EBS User Guide.
17

Amazon Elastic Compute Cloud

User Guide

Resource management
• Use instance metadata and custom resource tags to track and identify your AWS resources.
For more information, see Use instance metadata to manage your EC2 instance and Tag your
Amazon EC2 resources.
• View your current limits for Amazon EC2. Plan to request any limit increases in advance of the
time that you'll need them. For more information, see Amazon EC2 service quotas.
• Use AWS Trusted Advisor to inspect your AWS environment, and then make recommendations
when opportunities exist to save money, improve system availability and performance, or help
close security gaps. For more information, see AWS Trusted Advisor in the AWS Support User
Guide.
Backup and recovery
• Regularly back up your EBS volumes using Amazon EBS snapshots, and create an Amazon
Machine Image (AMI) from your instance to save the configuration as a template for launching
future instances. For more information about AWS services that help achieve this use case, see
AWS Backup and Amazon Data Lifecycle Manager.
• Deploy critical components of your application across multiple Availability Zones, and replicate
your data appropriately.
• Design your applications to handle dynamic IP addressing when your instance restarts. For more
information, see Amazon EC2 instance IP addressing.
• Monitor and respond to events. For more information, see Monitor Amazon EC2 resources.
• Ensure that you are prepared to handle failover. For a basic solution, you can manually attach
a network interface or Elastic IP address to a replacement instance. For more information, see
Elastic network interfaces. For an automated solution, you can use Amazon EC2 Auto Scaling. For
more information, see the Amazon EC2 Auto Scaling User Guide.
• Regularly test the process of recovering your instances and Amazon EBS volumes to ensure data
and services are restored successfully.
Networking
• Set the time-to-live (TTL) value for your applications to 255, for IPv4 and IPv6. If you use a
smaller value, there is a risk that the TTL will expire while application traffic is in transit, causing
reachability issues for your instances.

18

Amazon Elastic Compute Cloud

User Guide

Amazon Machine Images in Amazon EC2
An Amazon Machine Image (AMI) is an image that provides the software that is required to set up
and boot an Amazon EC2 instance. Each AMI also contains a block device mapping that specifies
the block devices to attach to the instances that you launch. You must specify an AMI when you
launch an instance. The AMI must be compatible with the instance type that you chose for your
instance. You can use an AMI provided by AWS, a public AMI, an AMI that someone else shared with
you, or an AMI that you purchased from the AWS Marketplace.
An AMI is specific to the following:
• Region
• Operating system
• Processor architecture
• Root device type
• Virtualization type
You can launch multiple instances from a single AMI when you require multiple instances with the
same configuration. You can use different AMIs to launch instances when you require instances
with different configurations, as shown in the following diagram.

19

Amazon Elastic Compute Cloud

User Guide

You can create an AMI from your Amazon EC2 instances and then use it to launch instances with
the same configuration. You can copy an AMI to another AWS Region, and then use it to launch
instances in that Region. You can also share an AMI that you created with other accounts so that
they can launch instances with the same configuration. You can sell your AMI using the AWS
Marketplace.
Contents
• AMI types and characteristics in Amazon EC2
• Find an AMI that meets the requirements for your EC2 instance
• Paid AMIs in the AWS Marketplace for Amazon EC2 instances
• Amazon EC2 AMI lifecycle
• Instance launch behavior with Amazon EC2 boot modes
• Use encryption with EBS-backed AMIs
• Understand shared AMI usage in Amazon EC2
• Monitor AMI events using Amazon EventBridge
• Understand AMI billing information
• AMI quotas in Amazon EC2
20

Amazon Elastic Compute Cloud

User Guide

AMI types and characteristics in Amazon EC2
When you launch an instance, the AMI that you choose must be compatible with the instance type
that you choose. You can select an AMI to use based on the following characteristics:
• Region
• Operating system
• Processor architecture
• Launch permissions
• Root device type
• Virtualization types

Launch permissions
Launch permissions determine who can use an AMI to launch instances. You can think of launch
permissions as sharing an AMI—when you grant launch permissions, you're sharing the AMI
with other users. Only the owner of an AMI can determine its availability by specifying launch
permissions. Launch permissions fall into the following categories.
Launch
permission

Description

public

The owner grants launch permissions to all AWS accounts.

explicit

The owner grants launch permissions to specific AWS accounts, organizat
ions, or organizational units (OUs).

implicit

The owner has implicit launch permissions for an AMI.

Amazon and the Amazon EC2 community provide a large selection of public AMIs. For more
information, see Understand shared AMI usage in Amazon EC2. Developers can charge for their
AMIs. For more information, see Paid AMIs in the AWS Marketplace for Amazon EC2 instances.

Root device type
All AMIs are categorized as either backed by Amazon EBS or backed by instance store.
AMI characteristics

21

Amazon Elastic Compute Cloud

User Guide

• Amazon EBS-backed AMI – The root device for an instance launched from the AMI is an Amazon
Elastic Block Store (Amazon EBS) volume created from an Amazon EBS snapshot. Supported for
both Linux and Windows AMIs.
• Amazon instance store-backed AMI – The root device for an instance launched from the AMI is an
instance store volume created from a template stored in Amazon S3. Supported for Linux AMIs
only. Windows AMIs do not support instance store for the root device.
For more information, see Root volumes for your Amazon EC2 instances.
Note
Instance store-backed AMIs are considered end of life and are not recommended for new
usage. They are only supported on the following older instance types: C1, C3, D2, I2, M1,
M2, M3, R3, and X1.

The following table summarizes the important differences when using the two types of AMIs.
Characteristic

Amazon EBS-backed AMI

Amazon instance store-backed
AMI

Root device volume

EBS volume

Instance store volume

Boot time for an
instance

Usually less than 1 minute

Usually less than 5 minutes

By default, the root volume
is deleted when the instance
terminates.* Data on any other
EBS volumes persists after
instance termination by default.

Data on any instance store
volumes persists only during the
life of the instance.

Can be in a stopped state. Even
when the instance is stopped and
not running, the root volume is
persisted in Amazon EBS.

Cannot be in a stopped state;
instances are running or
terminated.

Data persistence

Stopped state

Root device type

22

Amazon Elastic Compute Cloud

Characteristic

Modifications

Charges

AMI creation/bundling

User Guide

Amazon EBS-backed AMI

Amazon instance store-backed
AMI

The instance type, kernel, RAM
disk, and user data can be
changed while the instance is
stopped.

Instance attributes are fixed for
the life of an instance.

You're charged for instance
usage, EBS volume usage, and
storing your AMI as an EBS snaps
hot.

You're charged for instance usage
and storing your AMI in Amazon
S3.

Uses a single command/call

Requires installation and use of
AMI tools

* By default, EBS root volumes have the DeleteOnTermination flag set to true. For information
about how to change this flag so that the volume persists after termination, see Keep an Amazon
EBS root volume after an Amazon EC2 instance terminates.
** Supported with io2 EBS Block Express only. For more information, see Provisioned IOPS SSD
Block Express volumes in the Amazon EBS User Guide.

Determine the root device type of your AMI
The AMI that you use to launch an EC2 instance determines the type of the root volume. The root
volume of an EC2 instance is either an EBS volume or an instance store volume.
Nitro-based instances support only EBS root volumes. The following previous generation instance
types are the only instance types that support instance store root volumes: C1, C3, D2, I2, M1, M2,
M3, R3, and X1.
Console
To determine the root device type of an AMI
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

Determine the AMI root device type

23

Amazon Elastic Compute Cloud

User Guide

Amazon EC2 instances
An Amazon EC2 instance is a virtual server in the AWS cloud environment. You have full control
over your instance, from the time that you first start it (referred to as launching an instance) until
you delete it (referred to as terminating an instance). You can choose from a variety of operating
systems when you launch your instance. You can connect to your instance and customize it to meet
your needs. For example, you can configure the operating system, install operating system updates,
and install applications on your instance.
Amazon EC2 provides a wide range of instance types. You can choose an instance type that
provides the compute resources, memory, storage, and network performance that you need to run
your applications.
With Amazon EC2, you pay only for what you use. Billing for your instance starts when you launch
your instance and it transitions to the running state. Billing stops when you stop your instance and
resumes when you start your instance. When you terminate your instance, billing stops when it
transitions to the shutting down state.
Amazon EC2 provides features that you can use to optimize the performance and the cost of
your instances. For example, you can use Amazon EC2 Fleet or Amazon EC2 Auto Scaling to scale
your capacity up or down as your instance utilization changes. You can reduce the costs for your
instances using Spot Instances or Savings Plans.
A managed instance is managed by a service provider, such as Amazon EKS Auto Mode. You can’t
directly modify the settings of a managed instance. Managed instances are identified by a true
value in the Managed field. For more information, see Amazon EC2 managed instances.
Features and tasks
• Amazon EC2 instance types
• Amazon EC2 managed instances
• Amazon EC2 billing and purchasing options
• Store instance launch parameters in Amazon EC2 launch templates
• Launch an Amazon EC2 instance
• Connect to your EC2 instance
• Amazon EC2 instance state changes
267

Amazon Elastic Compute Cloud

User Guide

• Automatic instance recovery
• Use instance metadata to manage your EC2 instance
• Detect whether a host is an EC2 instance
• Instance identity documents for Amazon EC2 instances
• Precision clock and time synchronization on your EC2 instance
• Manage device drivers for your EC2 instance
• Configure your Amazon EC2 Windows instance
• Upgrade an EC2 Windows instance to a newer version of Windows Server
• Tutorial: Connect an Amazon EC2 instance to an Amazon RDS database

Amazon EC2 instance types
When you launch an instance, the instance type that you specify determines the hardware of the
host computer used for your instance. Each instance type offers different compute, memory, and
storage capabilities, and is grouped in an instance family based on these capabilities. Select an
instance type based on the requirements of the application or software that you plan to run on
your instance. For more information about features and use cases, see Amazon EC2 Instance Types.
Amazon EC2 dedicates some resources of the host computer, such as CPU, memory, and instance
storage, to a particular instance. Amazon EC2 shares other resources of the host computer, such as
the network and the disk subsystem, among instances. If each instance on a host computer tries
to use as much of one of these shared resources as possible, each receives an equal share of that
resource. However, when a resource is underused, an instance can consume a higher share of that
resource while it's available.
Each instance type provides higher or lower minimum performance from a shared resource. For
example, instance types with high I/O performance have a larger allocation of shared resources.
Allocating a larger share of shared resources also reduces the variance of I/O performance. For
most applications, moderate I/O performance is more than enough. However, for applications that
require greater or more consistent I/O performance, consider an instance type with higher I/O
performance.
Contents
• Available instance types
• Hardware specifications
Instance types

268

Amazon Elastic Compute Cloud

User Guide

• Hypervisor type
• AMI virtualization types
• Processors
• Find an Amazon EC2 instance type
• Get recommendations from EC2 instance type finder
• Get EC2 instance recommendations from Compute Optimizer
• Amazon EC2 instance type changes
• Burstable performance instances
• Performance acceleration with GPU instances
• Amazon EC2 Mac instances
• Amazon EBS-optimized instance types
• CPU options for Amazon EC2 instances
• AMD SEV-SNP for Amazon EC2 instances
• Processor state control for Amazon EC2 Linux instances

Available instance types
Amazon EC2 provides a wide selection of instance types optimized to fit different use cases.
Instance types comprise varying combinations of CPU, memory, storage, and networking capacity
and give you the flexibility to choose the appropriate mix of resources for your applications. Each
instance type includes one or more instance sizes, allowing you to scale your resources to the
requirements of your target workload.
Instance type naming conventions
Names are based on instance family, generation, processor family, capabilities, and size. For more
information, see Naming conventions in the Amazon EC2 Instance Types Guide.
Find an instance type
To determine which instance types meet your requirements, such as supported Regions, compute
resources, or storage resources, see Find an Amazon EC2 instance type and Amazon EC2 instance
type specifications in the Amazon EC2 Instance Types Guide.
Available instance types

269

Amazon Elastic Compute Cloud

User Guide

• Launch a container instance using an Inf1 or Inf2 instance and an Amazon ECS-optimized AMI.
For more information, see Amazon Linux 2 (Inferentia) AMIs in the Amazon Elastic Container
Service Developer Guide.
• Create an Amazon EKS cluster with nodes running Inf1 instances. For more information, see
Inferentia support in the Amazon EKS User Guide.

Find an Amazon EC2 instance type
Before you can launch an instance, you must select an instance type to use. The instance type
that you choose might depend on the resources that your workload requires, such as compute,
memory, or storage resources. It can be beneficial to identify several instance types that might suit
your workload and evaluate their performance in a test environment. There is no substitute for
measuring the performance of your application under load.
You can get suggestions and guidance for EC2 instance types using the EC2 instance type finder.
For more information, see the section called “EC2 instance type finder”.
If you already have running EC2 instances, you can use AWS Compute Optimizer to get
recommendations about the instance types that you should use to improve performance,
save money, or both. For more information, see the section called “Compute Optimizer
recommendations”.
Tasks
• Find an instance type using the console
• Describe an instance type using the AWS CLI
• Find an instance type using the AWS CLI
• Find an instance type using the Tools for PowerShell

Find an instance type using the console
You can find an instance type that meets your needs using the Amazon EC2 console.
To find an instance type using the console
1.

Open the Amazon EC2 console at https://console.aws.amazon.com/ec2/.

2.

From the navigation bar, select the Region in which to launch your instances. You can select
any Region that's available to you, regardless of your location.

Find an instance type

274

Amazon Elastic Compute Cloud

User Guide

3.

In the navigation pane, choose Instance Types.

4.

(Optional) Choose the preferences (gear) icon to select which instance type attributes to
display, such as On-Demand Linux pricing, and then choose Confirm. Alternatively, select the
name of an instance type to open its details page and view all attributes available through
the console. The console does not display all the attributes available through the API or the
command line.

5.

Use the instance type attributes to filter the list of displayed instance types to only the
instance types that meet your needs. For example, you can filter on the following attributes:
• Availability zones – The name of the Availability Zone, Local Zone, or Wavelength Zone. For
more information, see the section called “Regions and Zones”.
• vCPUs or Cores – The number of vCPUs or cores.
• Memory (GiB) – The memory size, in GiB.
• Network performance – The network performance, in Gigabits.
• Local instance storage – Indicates whether the instance type has local instance storage
(true | false).

6.

(Optional) To see a side-by-side comparison, select the checkbox for multiple instance types.
The comparison is displayed at the bottom of the screen.

7.

(Optional) To save the list of instance types to a comma-separated values (.csv) file for further
review, choose Actions, Download list CSV. The file includes all instance types that match the
filters you set.

8.

(Optional) To launch instances using an instance type that meet your needs, select the
checkbox for the instance type and choose Actions, Launch instance. For more information,
see Launch an EC2 instance using the launch instance wizard in the console.

Describe an instance type using the AWS CLI
You can use the describe-instance-types command to describe a specific instance type.
To fully describe an instance type
The following command displays all available details for the specified instance type. The output is
lengthy, so it is omitted here.
aws ec2 describe-instance-types \
--instance-types t2.micro \
Find an instance type

275

Amazon Elastic Compute Cloud

User Guide

EC2 Fleet and Spot Fleet
EC2 Fleet and Spot Fleet are designed to be a useful way to launch a fleet of tens, hundreds,
or thousands of Amazon EC2 instances in a single operation. Each instance in a fleet is either
configured by a launch template or a set of launch parameters that you configure manually at
launch.
Topics
• Features and benefits
• Which is the best fleet method to use?
• Configuration options for your EC2 Fleet or Spot Fleet
• Work with EC2 Fleet
• Work with Spot Fleet
• Monitor your EC2 Fleet or Spot Fleet
• Tutorials for EC2 Fleet
• Example CLI configurations for EC2 Fleet
• Example CLI configurations Spot Fleet
• Quotas for EC2 Fleet and Spot Fleet

Features and benefits
Fleets provide the following features and benefits, enabling you to maximize cost savings and
optimize availability and performance when running applications on multiple EC2 instances.
Multiple instance types
A fleet can launch multiple instance types, ensuring it isn't dependent on the availability of any
single instance type. This increases the overall availability of instances in your fleet.
Distributing instances across Availability Zones
A fleet automatically attempts to distribute instances evenly across multiple Availability Zones
for high availability. This provides resiliency in case an Availability Zone becomes unavailable.

Features and benefits

1933

Amazon Elastic Compute Cloud

User Guide

Multiple purchasing options
A fleet can launch multiple purchase options (Spot and On-Demand Instances), allowing you to
optimize costs through Spot Instance usage. You can also take advantage of Reserved Instance
and Savings Plans discounts by using them in conjunction with On-Demand Instances in the
fleet.
Automated replacement of Spot Instances
If your fleet includes Spot Instances, it can automatically request replacement Spot capacity if
your Spot Instances are interrupted. Through Capacity Rebalancing, a fleet can also monitor and
proactively replace your Spot Instances that are at an elevated risk of interruption.
Reserve On-Demand capacity
A fleet can use an On-Demand Capacity Reservation to reserve On-Demand capacity. A fleet can
also include Capacity Blocks for ML, allowing you to reserve GPU instances on a future date to
support short duration machine learning (ML) workloads.

Which is the best fleet method to use?
As a general best practice, we recommend launching fleets of Spot and On-Demand Instances with
Amazon EC2 Auto Scaling because it provides additional features you can use to manage your fleet.
The list of additional features includes automatic health check replacements for both Spot and OnDemand Instances, application-based health checks, and an integration with Elastic Load Balancing
to ensure an even distribution of application traffic to your healthy instances. You can also use
Auto Scaling groups when you use AWS services such as Amazon ECS, Amazon EKS (self-managed
node groups), and Amazon VPC Lattice. For more information, see the Amazon EC2 Auto Scaling
User Guide.
If you can't use Amazon EC2 Auto Scaling, then you might consider using EC2 Fleet or Spot Fleet.
EC2 Fleet and Spot Fleet offer the same core functionality. However, EC2 Fleet is only available
using a command line and does not provide console support. Spot Fleet provides console support,
but is based on a legacy API with no planned investment.
Use the following table to determine which fleet method to use.

Which fleet method to use?

1934

Amazon Elastic Compute Cloud

User Guide

Fleet method

When to use?

Use case

Amazon EC2 Auto Scaling

• You need multiple
instances with either a
single configuration or a
mixed configuration.

Create an Auto Scaling group
that manages the lifecycle of
your instances while maintaini
ng the desired number of
instances. Supports horizontal
scaling (adding more instances
) between specified minimum

• You want to automate the
lifecycle management of
your instances.
EC2 Fleet

• You need multiple
instances with either a
single configuration or a
mixed configuration.
• You want to self-manage
your instance lifecycle.
• If you don’t need auto
scaling, we recommend
that you use an instant
type EC2 Fleet.

and maximum limits.
Create an instant fleet of
both On-Demand Instances
and Spot Instances in a single
operation, with multiple
launch specifications that
vary by instance type, AMI,
Availability Zone, or subnet.
The Spot Instance allocation
strategy defaults to lowestprice per unit, but we
recommend changing it to
price-capacity-opt
imized .

Spot Fleet

• We strongly discourage
using Spot Fleet because
it is based on a legacy API
with no planned investmen
t.

Use Spot Fleet only if you
need console support for a
use case for when you would
use EC2 Fleet.

• If you want to manage
your instance lifecycle,
rather use EC2 Fleet.
• If you don't want to
manage your instance

Which fleet method to use?

1935

Amazon Elastic Compute Cloud

Fleet method

User Guide

When to use?

Use case

lifecycle, rather use an
Auto Scaling group.

Configuration options for your EC2 Fleet or Spot Fleet
When planning your EC2 Fleet or Spot Fleet, we recommend that you consider the following
options when deciding how to configure your fleet.

Configura
tion
option

Question

Documentation

Fleet
request
type

Do you want a fleet that submits a one-time
request for the desired target capacity, or a fleet
that maintains target capacity over time?

EC2 Fleet and Spot Fleet
request types

Spot
Instances

Do you plan to include Spot Instances in your
fleet? Review the Spot best practices and use
them when you plan your fleet so that you can
provision the instances at the lowest possible
price.

Best practices for Amazon
EC2 Spot

Spending
limit for
your fleet

Do you want to limit how much you'll pay for
your fleet per hour?

Set a spending limit for your
EC2 Fleet or Spot Fleet

Instance
types and
attribute
-based
instance
type
selection

Do you want to specify the instance types in
your fleet, or let Amazon EC2 select the instance
types that meet your application requirements?

Specify attributes for instance
type selection for EC2 Fleet
or Spot Fleet

Configuration options

1936

Amazon Elastic Compute Cloud

User Guide

Configura
tion
option

Question

Documentation

Instance
weighting

Do you want to assign weights to each instance
type to represent their compute capacity and
performance, so that Amazon EC2 can select any
combination of available instance types to fulfil
your desired target capacity?

Use instance weighting to
manage cost and performanc
e of your EC2 Fleet or Spot
Fleet

Allocation
strategies

Do you want to decide whether to optimize for
available capacity, price, or instance types to use
for the Spot Instances and On-Demand Instances
in your fleet?

Use allocation strategies to
determine how EC2 Fleet or
Spot Fleet fulfills Spot and
On-Demand capacity

Capacity
Rebalanci
ng

Do you want your fleet to automatically replace
at-risk Spot Instances?

Use Capacity Rebalancing in
EC2 Fleet and Spot Fleet to
replace at-risk Spot Instances

OnDemand
Capacity
Reservati
on

Do you want to reserve capacity for the OnDemand Instances in your fleet?

Use Capacity Reservations to
reserve On-Demand capacity
in EC2 Fleet

EC2 Fleet and Spot Fleet request types
The request type for an EC2 Fleet or Spot Fleet determines whether the request is synchronous or
asynchronous, and whether it is a one-time request for the desired target capacity or an ongoing
effort to maintain the capacity over time. When configuring your fleet, you must specify the
request type.
Both EC2 Fleet and Spot Fleet offer two request types: request and maintain. In addition, EC2
Fleet offers a third request type called instant.

Request types

1937

Amazon Elastic Compute Cloud

User Guide

Fleet request types
instant (EC2 Fleet only)
If you configure the request type as instant, EC2 Fleet places a synchronous one-time request
for your desired capacity. In the API response, it returns the instances that launched and
provides errors for those instances that could not be launched. For more information, see
Configure an EC2 Fleet of type instant.
request
If you configure the request type as request, the fleet places an asynchronous one-time
request for your desired capacity. If capacity diminishes due to Spot interruptions, the fleet does
not attempt to replenish Spot Instances, nor does it submit requests in alternative Spot capacity
pools if capacity is unavailable. When creating a Spot Fleet of type request using the console,
clear the Maintain target capacity checkbox.
maintain (default)
If you configure the request type as maintain, the fleet places an asynchronous request for
your desired capacity, and maintains it by automatically replenishing any interrupted Spot
Instances. When creating a Spot Fleet of type maintain using the console, select the Maintain
target capacity checkbox

Configure an EC2 Fleet of type instant
The EC2 Fleet of type instant is a synchronous one-time request that makes only one attempt to
launch your desired capacity. The API response lists the instances that launched, along with errors
for those instances that could not be launched. There are several benefits to using an EC2 Fleet of
type instant, which are described in this article. Example configurations are provided at the end of
the article.
For workloads that need a launch-only API to launch EC2 instances, you can use the RunInstances
API. However, with RunInstances, you can only launch On-Demand Instances or Spot Instances, but
not both in the same request. Furthermore, when you use RunInstances to launch Spot Instances,
your Spot Instance request is limited to one instance type and one Availability Zone. This targets
a single Spot capacity pool (a set of unused instances with the same instance type and Availability
Zone). If the Spot capacity pool does not have sufficient Spot Instance capacity for your request,
the RunInstances call fails.
Request types

1938

Amazon Elastic Compute Cloud

User Guide

Instead of using RunInstances to launch Spot Instances, we recommend that you rather use the
CreateFleet API with the type parameter set to instant for the following benefits:
• Launch On-Demand Instances and Spot Instances in one request. An EC2 Fleet can launch OnDemand Instances, Spot Instances, or both. The request for Spot Instances is fulfilled if there is
available capacity and the maximum price per hour for your request exceeds the Spot price.
• Increase the availability of Spot Instances. By using an EC2 Fleet of type instant, you can
launch Spot Instances following Spot best practices with the resulting benefits:
• Spot best practice: Be flexible about instance types and Availability Zones.
Benefit: By specifying several instance types and Availability Zones, you increase the number
of Spot capacity pools. This gives the Spot service a better chance of finding and allocating
your desired Spot compute capacity. A good rule of thumb is to be flexible across at least 10
instance types for each workload and make sure that all Availability Zones are configured for
use in your VPC.
• Spot best practice: Use the price-capacity-optimized allocation strategy.
Benefit: The price-capacity-optimized allocation strategy identifies instances from the
most-available Spot capacity pools, and then automatically provisions instances from the
lowest priced of these pools. Because your Spot Instance capacity is sourced from pools with
optimal capacity, this decreases the possibility that your Spot Instances will be interrupted
when Amazon EC2 needs the capacity back.
• Get access to a wider set of capabilities. For workloads that need a launch-only API, and where
you prefer to manage the lifecycle of your instance rather than let EC2 Fleet manage it for
you, use the EC2 Fleet of type instant instead of the RunInstances API. EC2 Fleet provides
a wider set of capabilities than RunInstances, as demonstrated in the following examples.
For all other workloads, you should use Amazon EC2 Auto Scaling because it supplies a more
comprehensive feature set for a wide variety of workloads, like ELB-backed applications,
containerized workloads, and queue processing jobs.
You can use EC2 Fleet of type instant to launch instances into Capacity Blocks. For more
information, see Tutorial: Configure your EC2 Fleet to launch instances into Capacity Blocks.
AWS services like Amazon EC2 Auto Scaling and Amazon EMR use EC2 Fleet of type instant to
launch EC2 instances.

Request types

1939

Amazon Elastic Compute Cloud

User Guide

Prerequisites for EC2 Fleet of type instant
For the prerequisites for creating an EC2 Fleet, see EC2 Fleet prerequisites.
How instant EC2 Fleet works
When working with an EC2 Fleet of type instant, the sequence of events is as follows:
1. Configure: Configure the CreateFleet request type as instant. For more information, see
Create an EC2 Fleet. Note that after you make the API call, you can't modify it.
2. Request: When you make the API call, Amazon EC2 places a synchronous one-time request for
your desired capacity.
3. Response: The API response lists the instances that launched, along with errors for those
instances that could not be launched.
4. Describe: You can describe your EC2 Fleet, list the instances associated with your EC2 Fleet, and
view the history of your EC2 Fleet.
5. Terminate instances: You can terminate the instances at any time.
6. Delete fleet request: The fleet request can be deleted either manually or automatically:
• Manual: You can delete the fleet request after your instances launch.
Note that a deleted instant fleet with running instances is not supported. When you delete
an instant fleet, Amazon EC2 automatically terminates all its instances. For fleets with
more than 1000 instances, the deletion request might fail. If your fleet has more than 1000
instances, first terminate most of the instances manually, leaving 1000 or fewer. Then delete
the fleet, and the remaining instances will be terminated automatically.
• Automatic: Amazon EC2 deletes the fleet request some time after either:
• All the instances are terminated.
• The fleet fails to launch any instances.
Examples
The following examples show how to use EC2 Fleet of type instant for different use cases. For
more information about using the EC2 CreateFleet API parameters, see CreateFleet in the Amazon
EC2 API Reference.
Examples
• Example 1: Launch Spot Instances with the capacity-optimized allocation strategy
Request types

1940

Amazon Elastic Compute Cloud

User Guide

Networking in Amazon EC2
Amazon VPC enables you to launch AWS resources, such as Amazon EC2 instances, into a virtual
network dedicated to your AWS account, known as a virtual private cloud (VPC). When you launch
an instance, you can select a subnet from the VPC. The instance is configured with a primary
network interface, which is a logical virtual network card. The instance receives a primary private IP
address from the IPv4 address of the subnet, and it is assigned to the primary network interface.
You can control whether the instance receives a public IP address from Amazon's pool of public
IP addresses. The public IP address of an instance is associated with your instance only until it is
stopped or terminated. If you require a persistent public IP address, you can allocate an Elastic IP
address for your AWS account and associate it with an instance or a network interface. An Elastic IP
address remains associated with your AWS account until you release it, and you can move it from
one instance to another as needed. You can bring your own IP address range to your AWS account,
where it appears as an address pool, and then allocate Elastic IP addresses from your address pool.
To increase network performance and reduce latency, you can launch instances in a placement
group. You can get significantly higher packet per second (PPS) performance using enhanced
networking. You can accelerate high performance computing and machine learning applications
using an Elastic Fabric Adapter (EFA), which is a network device that you can attach to a supported
instance type.
Features
• Regions and Zones
• Amazon EC2 instance IP addressing
• EC2 instance hostnames and domains
• Bring your own IP addresses (BYOIP) to Amazon EC2
• Elastic IP addresses
• Elastic network interfaces
• Amazon EC2 instance network bandwidth
• Enhanced networking on Amazon EC2 instances
• Elastic Fabric Adapter for AI/ML and HPC workloads on Amazon EC2
• Amazon EC2 instance topology
• Placement groups for your Amazon EC2 instances
2176

Amazon Elastic Compute Cloud

User Guide

• Network maximum transmission unit (MTU) for your EC2 instance
• Virtual private clouds for your EC2 instances

Regions and Zones
Amazon EC2 is hosted in multiple locations world-wide. These locations are composed of AWS
Regions, Availability Zones, Local Zones, AWS Outposts, and Wavelength Zones.
• Regions are separate geographic areas.
• Availability Zones are multiple, isolated locations within each Region.
• Local Zones provide you with the ability to place resources, such as compute and storage, in
multiple locations closer to your end users.
• Wavelength Zones provide you with the ability to build applications that deliver ultra-low
latencies to 5G devices and end users. Wavelength deploys standard AWS compute and storage
services to the edge of telecommunication carriers' 5G networks.
• AWS Outposts brings native AWS services, infrastructure, and operating models to virtually any
data center, colocation space, or on-premises facility.
AWS operates state-of-the-art, highly available data centers. Although rare, failures can occur that
affect the availability of instances that are in the same location. If you host all of your instances in a
single location that is affected by a failure, none of your instances would be available.
For more information, see AWS Global Infrastructure.
Contents
• Regions
• Availability Zones
• Local Zones
• Wavelength Zones
• AWS Outposts

Regions
Each Region is designed to be isolated from the other Regions. This achieves the greatest possible
fault tolerance and stability.
Regions and Zones

2177

Amazon Elastic Compute Cloud

User Guide

When you launch an instance, select a Region that puts your instances close to specific customers,
or that meets the legal or other requirements that you have. You can launch instances in multiple
Regions.
When you view your resources, you see only the resources that are tied to the Region that you
specified. This is because Regions are isolated from each other, and we don't automatically
replicate resources across Regions.

Available Regions
For the list of available Regions, see AWS Regions.

Regional endpoints for Amazon EC2
When you work with an instance using the command line interface or API actions, you must specify
its Regional endpoint. For more information about the Regions and endpoints for Amazon EC2, see
Amazon EC2 service endpoints in the Amazon EC2 Developer Guide.
For more information, see AWS Regions in the AWS Regions and Availability Zones User Guide.

Availability Zones
Each Region has multiple, isolated locations known as Availability Zones. The code for an
Availability Zone is its Region code followed by a letter identifier. For example, us-east-1a.
By launching EC2 instances in multiple Availability Zones, you can protect your applications from
the failure of a single location in the Region.
The following diagram illustrates multiple Availability Zones in an AWS Region. Availability Zone A
and Availability Zone B each have one subnet, and each subnet has EC2 instances. Availability Zone
C has no subnets, therefore you can't launch instances into this Availability Zone.

Availability Zones

2178

Amazon Elastic Compute Cloud

User Guide

For more information, see Virtual private clouds for your EC2 instances.

Availability Zones by Region
For the list of Availability Zones by Region, see AWS Availability Zones.

Instances in Availability Zones
When you launch an instance, you select a Region and a virtual private cloud (VPC). Then, you
can either select a subnet from one of the Availability Zones or let us choose a subnet for you.
When you launch your initial instances, we recommend that you let us select an Availability Zone
for you based on system health and available capacity. If you launch additional instances, specify
an Availability Zone only if your new instances must be close to, or separated from, your existing
instances.
If you distribute instances across multiple Availability Zones and an instance fails, you can design
your application so that an instance in another Availability Zone handles requests instead.
For more information, see AWS Availability Zones in the AWS Regions and Availability Zones User
Guide.
Availability Zones

2179