Home / AWS / Fix AWS EC2 Instance Not Starting

AWS

Fix AWS EC2 Instance Not Starting

Diagnose and resolve EC2 instance startup failures caused by capacity issues, EBS problems, AMI errors, and configuration conflicts.

Published: Apr 1, 20266 min readBy FixWikiHub Editorial Team

Abstract illustration for a troubleshooting knowledge base category.

Introduction

When you try to start an EC2 instance, it transitions from 'stopped' to 'pending', but instead of reaching 'running', it either fails immediately or gets stuck in pending state and then stops. The error could be at the hypervisor level, EBS level, network level, or within the instance itself.

Symptoms

In the AWS Console:

bash

Instance failed to start
State: stopped
State transition reason: Server.InternalError

Via AWS CLI:

bash

$ aws ec2 describe-instances --instance-ids i-1234567890abcdef0 --query 'Reservations[*].Instances[*].StateReason'
{
  "Code": "Server.InternalError",
  "Message": "Internal error on launch"
}

Common state reason codes:

Code	Meaning
`Server.InternalError`	AWS-side infrastructure issue
`Server.SpotInstanceTermination`	Spot capacity no longer available
`Client.VolumeLimitExceeded`	EBS volume limit reached
`Client.InsufficientInstanceCapacity`	Not enough host capacity
`Client.InvalidParameter`	Invalid configuration parameter

Common Causes

1.Insufficient capacity - AZ doesn't have available hosts for the instance type
2.EBS attachment failure - Volume doesn't exist, is in wrong AZ, or limit exceeded
3.AMI issues - AMI doesn't exist, is deregistered, or has wrong architecture
4.Security group limits - Too many rules or groups attached
5.ENI issues - Network interface doesn't exist or is attached elsewhere
6.Instance store conflicts - Instance store volumes not available
7.IAM instance profile - Profile doesn't exist or lacks permissions
8.Placement group - Can't fulfill placement constraints

Step-by-Step Fix

1.Check logs for specific error messages
2.Verify configuration settings
3.Test network connectivity
4.Review recent changes
5.Apply corrective action
6.Verify the fix

Step 1: Check State Reason and Error Code

bash

aws ec2 describe-instances --instance-ids i-1234567890abcdef0 \
  --query 'Reservations[*].Instances[*].[State.Name, StateReason.Code, StateReason.Message]'

This gives you the specific error code to diagnose.

Step 2: Check Capacity Issues

If Client.InsufficientInstanceCapacity:

```bash # Try a different AZ aws ec2 describe-instance-type-offerings --location-type availability-zone \ --filters Name=instance-type,Values=c5.2xlarge Name=location,Values=us-east-1a

# Check current capacity in region aws ec2 describe-instance-types --instance-types c5.2xlarge \ --query 'InstanceTypes[*].[InstanceType, FreeTierEligible]' ```

Solutions: - Launch in a different AZ - Try a different instance type - Use Spot instances with capacity-optimized allocation - Wait and retry (capacity fluctuates)

Step 3: Verify EBS Volumes

Check if volumes exist and are available:

```bash aws ec2 describe-volumes --filters Name=attachment.instance-id,Values=i-1234567890abcdef0

# Check all volumes in the correct AZ aws ec2 describe-volumes --filters Name=availability-zone,Values=us-east-1a ```

Verify volume limits:

bash

# Check your account EBS limits
aws service-quotas get-service-quota --service-code ebs --quota-code L-D18ECD67

Common issues: - Volume was deleted - Volume is in different AZ than the instance - Account reached maximum number of volumes - Volume is encrypted but KMS key is not accessible

Step 4: Check AMI and Architecture

```bash # Get instance's AMI aws ec2 describe-instances --instance-ids i-1234567890abcdef0 \ --query 'Reservations[*].Instances[*].ImageId'

# Verify AMI exists aws ec2 describe-images --image-ids ami-12345678

# Check AMI architecture matches instance type aws ec2 describe-images --image-ids ami-12345678 \ --query 'Images[*].[ImageId, Architecture, VirtualizationType]' ```

Issues: - AMI was deregistered - Architecture mismatch (arm64 vs x86_64) - AMI is not available in this region

Step 5: Check Network Configuration

Verify security groups and ENIs:

```bash # Check attached security groups aws ec2 describe-instances --instance-ids i-1234567890abcdef0 \ --query 'Reservations[*].Instances[*].SecurityGroups'

# Check ENI status aws ec2 describe-network-interfaces --filters Name=attachment.instance-id,Values=i-1234567890abcdef0

# Verify ENI exists aws ec2 describe-network-interfaces --network-interface-ids eni-12345 ```

Step 6: Check Instance Profile

```bash # Get instance profile aws ec2 describe-instances --instance-ids i-1234567890abcdef0 \ --query 'Reservations[*].Instances[*].IamInstanceProfile'

# Verify the role exists aws iam get-instance-profile --instance-profile-name my-instance-profile ```

If the role was deleted, the instance won't start.

Step 7: Check Console Output

For clues about why the instance stopped:

bash

aws ec2 get-console-output --instance-id i-1234567890abcdef0 --output text

Look for: - Kernel panic - Init system errors - Disk mounting failures - Network configuration errors

Step 8: Force Instance Recovery

If the host is having issues:

bash

# Stop and start (moves to a new host)
aws ec2 stop-instances --instance-ids i-1234567890abcdef0
aws ec2 start-instances --instance-ids i-1234567890abcdef0

Or for more drastic measures:

bash

# Create AMI from stopped instance and launch new
aws ec2 create-image --instance-id i-1234567890abcdef0 --name "recovery-image"

Step 9: Check for Instance Store Issues

If your instance uses instance store volumes:

bash

aws ec2 describe-instance-types --instance-types c5.2xlarge \
  --query 'InstanceTypes[*].InstanceStorageInfo'

Instance store volumes are ephemeral and data is lost when stopped. If the instance expects data on instance store that's no longer available, it may fail to start.

Verification

```bash # Check instance state aws ec2 describe-instances --instance-ids i-1234567890abcdef0 \ --query 'Reservations[*].Instances[*].State.Name'

# Should return: "running"

# Check system status aws ec2 describe-instance-status --instance-id i-1234567890abcdef0 ```

[Fix AWS EC2 Instance Stuck in Stopping State](/articles/fix-aws-ec2-instance-stuck-stopping)
[Fix AWS EC2 Status Check Failed](/articles/fix-aws-ec2-status-check-failed)
[Fix AWS EC2 EBS Volume Attachment Failed](/articles/fix-aws-ec2-ebs-volume-attachment-failed)

[AWS troubleshooting: Fix IAM Permission Denied - Complete Tro](fix-iam-permission-denied)
[AWS cloud troubleshooting: AWS ACM Certificate Pending Validation Because the](aws-acm-certificate-pending-validation-wrong-route53-zone)
[AWS cloud troubleshooting: AWS ALB Returns 502 Because the Target Closed the ](aws-alb-502-target-closed-connection-keepalive-timeout-mismatch)
[AWS cloud troubleshooting: Fix AWS ALB CreateListener TargetGroupNotFound Err](aws-alb-createlistener-targetgroupnotfound)
[AWS cloud troubleshooting: Fix Aws Alb Lambda 502 Bad Gateway Issue in AWS](aws-alb-lambda-502-bad-gateway)

Was this guide helpful?

Related search paths

People also search for

If the symptom is close but not identical, these search paths usually surface the right neighboring fixes faster than scrolling the full archive.

AWS EC2 Instance Not Starting AWS EC2 Instance Not Starting AWS AWS EC2 Instance Not Starting troubleshooting AWS EC2 Instance Not Starting fix Diagnose and resolve EC2 instance startup failures caused by capacity issues, EBS problems, AMI errors, and configuration conflicts AWS Diagnose and resolve EC2 instance startup failures caused by capacity issues, EBS problems, AMI errors, and configuration conflicts

Explore Related Topics

Browse Guides from Other Categories

Discover troubleshooting guides from related categories to expand your knowledge.

FAQ

AWS Troubleshooting FAQs

Common questions about troubleshooting and preventing similar issues

How do I know if this aws-errors troubleshooting guide applies to my situation?

This guide is designed for aws-errors issues. If you're experiencing similar symptoms described in the article, follow the step-by-step instructions. Start with the most common causes and work through the diagnostic process.

Is it safe to follow these aws-errors troubleshooting steps?

Yes, all steps are designed to be safe and non-destructive. We recommend creating backups before making significant changes and testing each step before proceeding to the next.

How long does it typically take to resolve this type of aws-errors issue?

Most aws-errors issues can be resolved within 30 minutes to 2 hours, depending on the complexity and root cause. Follow the troubleshooting flow to identify and fix the problem efficiently.

How can I prevent this aws-errors issue from happening again?

Regular maintenance, monitoring, and following best practices for aws-errors configuration can help prevent recurrence. Consider implementing automated checks and alerts for early detection.

Written by

FixWikiHub Editorial Team

Our editorial team consists of experienced DevOps engineers, systems administrators, and cloud architects with hands-on experience in production environments across AWS, Azure, GCP, and on-premises infrastructure.

Every guide undergoes technical review for accuracy and is updated when software versions, commands, or best practices change.

Last updated: Apr 1, 2026

About our team

Important Notice

Disclaimer & Safety Guidelines

The troubleshooting steps in this guide are provided for educational and informational purposes. Before applying any changes to production systems:

Test in a staging environment first — Always verify commands and configurations in a non-production environment before deploying to live systems.
Create backups — Ensure you have current backups of databases, configurations, and critical files before making changes.
Understand the impact — Review how each step may affect your specific environment, dependencies, and users.
Consult official documentation — This guide supplements, but does not replace, official vendor documentation and best practices.

FixWikiHub is not responsible for any damages arising from the use of this content. See our Terms of Use for more information.

Resources

Official Documentation & Further Reading

For authoritative information, consult the official documentation for the technologies discussed in this guide. Our troubleshooting content supplements, but does not replace, vendor documentation.

AWS Documentation — Official Amazon Web Services guides and API references
Kubernetes Documentation — Official Kubernetes documentation
Nginx Documentation — Official Nginx web server documentation
Apache Documentation — Official Apache HTTP Server documentation
Docker Documentation — Official Docker container documentation

Fix AWS EC2 Instance Not Starting

Introduction

Symptoms

Common Causes

Step-by-Step Fix

Step 1: Check State Reason and Error Code

Step 2: Check Capacity Issues

Step 3: Verify EBS Volumes

Step 4: Check AMI and Architecture

Step 5: Check Network Configuration

Step 6: Check Instance Profile

Step 7: Check Console Output

Step 8: Force Instance Recovery

Step 9: Check for Instance Store Issues

Verification

People also search for

Browse Guides from Other Categories

WordPress

SSL

DNS

AWS Troubleshooting FAQs

FixWikiHub Editorial Team

Disclaimer & Safety Guidelines

Official Documentation & Further Reading

Fix AWS EC2 Instance Not Starting

Introduction

Symptoms

Common Causes

Step-by-Step Fix

Step 1: Check State Reason and Error Code

Step 2: Check Capacity Issues

Step 3: Verify EBS Volumes

Step 4: Check AMI and Architecture

Step 5: Check Network Configuration

Step 6: Check Instance Profile

Step 7: Check Console Output

Step 8: Force Instance Recovery

Step 9: Check for Instance Store Issues

Verification

Related Issues

Related Articles

People also search for

Share this guide

More AWS Troubleshooting Guides

Browse Guides from Other Categories

AWS Troubleshooting FAQs

FixWikiHub Editorial Team

Disclaimer & Safety Guidelines

Official Documentation & Further Reading