The status checks automatically performed on Amazon EC2 instances are:

  • System Status Checks: These check the underlying systems used by the Amazon EC2 instance
  • Instance Status Checks: These check the configuration of the specific instance

See documentation: Status Checks for Your Instances

Often, an instance is available and ready to be used before these checks are complete -- this is especially the case for Linux instances because they boot very quickly.

If you receive a 1/2 checks passed message, either wait a little longer or Stop and Start the instance. Performing a Stop/Start will launch the instance on a different host, which will probably fix whatever problem was being experienced.

If the 1/2 checks passed message continues to appear after a Stop/Start, it is probably a misconfiguration of the AMI. I have seen this when the wrong virtualization type was selected for an AMI that was created from a Snapshot.

You might be able to get a hint about the problem by using the Get System Log command in the Actions menu, which shows the log while the instance is booting.

Worst case, launch a new instance from a known-good AMI, attach the non-booting volume as an additional disk and copy files to the new disk. You will still have access to your files even if it will not boot.

Answer from John Rotenstein on Stack Overflow
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Amazon Web Services
docs.aws.amazon.com › amazon ec2 › user guide › troubleshoot issues with amazon ec2 instances › troubleshoot amazon ec2 linux instances with failed status checks
Troubleshoot Amazon EC2 Linux instances with failed status checks - Amazon Elastic Compute Cloud
- Check root= (did the system wait for the right device?) - Missing modules (cat /proc/modules; ls /dev) FATAL: Could not load /lib/modules/2.6.34-4-virtual/modules.dep: No such file or directory FATAL: Could not load /lib/modules/2.6.34-4-virtual/modules.dep: No such file or directory ALERT! /dev/sda1 does not exist. Dropping to a shell! BusyBox v1.13.3 (Ubuntu 1:1.13.3-1ubuntu5) built-in shell (ash) Enter 'help' for a list of built-in commands.
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Amazon Web Services
docs.aws.amazon.com › amazon ec2 › user guide › monitor amazon ec2 resources › monitor the status of your amazon ec2 instances › status checks for amazon ec2 instances
Status checks for Amazon EC2 instances - Amazon Elastic Compute Cloud
These status checks detect underlying issues with the compute or Amazon EBS infrastructure. When the attached EBS status check metric fails, you can either wait for AWS to resolve the issue, or you can take actions, such as replacing the affected volumes or stopping and restarting the instance.
Top answer
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Hello. It sounds like you're encountering several issues with your Debian instance, particularly around SSH connectivity, instance status checks, and command execution errors Please follow below steps. **Check System Logs** * Go to the EC2 Console. * Select your instance. * Click on Actions > Monitor and troubleshoot > Get System Log. * Look for any error messages that might indicate what's wrong. **Stop and Start the Instance** * This action will migrate your instance to new hardware and might resolve underlying issues. * In the EC2 Console, select your instance. * Click on Instance State > Stop. * Once stopped, click on Instance State > Start. **Reinstall Basic Packages** * If you can SSH into your instance (even if it's slow), run the following commands to ensure basic utilities are installed ``` sudo apt update sudo apt install --reinstall coreutils ``` **Check PATH Variable** * If you see errors like -bash: id: command not found, it might indicate a problem with your PATH. Run ``` echo $PATH ``` * If it’s incorrect, temporarily fix it with ``` export PATH=$PATH:/usr/bin:/bin ``` **Monitor Resource Utilization** * Use the command top to check CPU and memory usage. * If the instance is overloaded, consider resizing it to a larger instance type. **Create a New Instance** * If the issues persist, consider launching a new instance from a known good AMI (Amazon Machine Image). * Reinstall your necessary software step by step to identify any potential issues. https://repost.aws/knowledge-center/ec2-linux-status-check-failure https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/connect-to-serial-console.html
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Hello, The "1/2 checks passed" issue on your EC2 instance likely points to a system or instance problem. Here's a quick way to troubleshoot: * Check System Logs: In the EC2 console, go to Actions > Monitor and troubleshoot > Get System Log. It may show the cause. * Stop/Start the Instance: This moves your instance to a new host, which may fix hardware issues. * Review File System: The errors ("-bash: id: command not found") suggest possible system configuration issues. Recheck system packages. * Use EC2 Serial Console: If SSH is slow, try the Serial Console to access your instance. https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/monitoring-system-instance-status-check.html
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Balaji S
balajidevops.hashnode.dev › troubleshooting-aws-ec2-instance-status-checks-a-comprehensive-guide
Troubleshooting AWS EC2 Instance Status Checks: A Comprehensive Guide
January 30, 2024 - When managing AWS EC2 instances, encountering a "1/2 checks passed" status check results can be a cause for concern. This status indicates that one of the two crucial status checks – system status check and instance status check – has failed.
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Server Fault
serverfault.com › questions › 1047484 › aws-ec2-1-2-checks-passed-error-instance-reachability-check-failed
amazon web services - AWS EC2 - 1/2 checks passed Error. Instance reachability check failed - Server Fault
I have a Ubuntu-20.4 ec2 instance. In that, I'm running a Django Application connected with Apache Server. I created this instance 20 days back and have never stopped the instance until yesterday. Suddenly today I cannot start the instance because of the Status Check error.
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Server Fault
serverfault.com › questions › 1115050 › aws-ec2-windows-instance-1-2-status-check
amazon web services - AWS EC2 windows instance 1/2 status check - Server Fault
Did you look at the AWS documentation? There are two status checks, which one failed? Suggest you edit your question to give more information and tell us the problem you're experiencing. ... I converted my ec2 instance running on windows server 2016 from m5.large to m6a.large, type change successful, Problem is: 1. but Instance status checks : failed 2...
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GeeksforGeeks
geeksforgeeks.org › devops › aws-ec2-status-checks
AWS EC2 Status Checks - GeeksforGeeks
July 23, 2025 - 1/2 checks passed (System check failed): The instance status check passed, but the system status check failed.
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Stack Overflow
stackoverflow.com › questions › 51338207 › ec2-1-2-checks-passed-every-2-or-3-days
amazon ec2 - Ec2 1/2 checks passed every 2 or 3 days - Stack Overflow
It is quite rare to have the instance status check fail after some period of time — it normally has problems at initial startup. This suggests that something is going wrong with your operating system, but that should be corrected by a reboot, ...
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AWS re:Post
repost.aws › questions › QUcD0A7gmqRsm6SGK-LuSgVA › ec-2-instance-randomly-fails-1-2-status-checks-at-4-30-am-with-no-user-activity-ssh-and-ap-is-become-unresponsive
EC2 instance randomly fails 1/2 status checks at 4:30 AM with no user activity — SSH and APIs become unresponsive | AWS re:Post
March 18, 2025 - When this happens, the instance becomes completely unresponsive — I can’t SSH in, and all APIs stop working. The only way to recover is to manually stop and start the instance via the AWS console.
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Stack Overflow
stackoverflow.com › questions › 59064996 › aws-ec2-instance-status-checks-1-2-checks-passed-ubuntu
amazon web services - AWS EC2 Instance Status Checks 1/2 checks passed ubuntu - Stack Overflow
When I have done all the steps somehow my live EC2 stop working(1/2 checks passed, Instance Status Checks - These checks monitor your software and network configuration for this instance.) with 504 Gateway time out. It also not working on CLI or Putty. It gives me port 22 timeout. I have checked Inbound & Outbound rules also. All port(22,80,443) is open publicly. Out bound is set to All port. I dont understand what's preventing it to connect. ... Yes it it attached! ... System log should give you the reason for the failure.
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AWS re:Post
repost.aws › knowledge-center › ec2-linux-status-check-failure
Troubleshoot status check failures on an unreachable EC2 Linux instance | AWS re:Post
June 2, 2025 - High memory pressure can cause an instance status check failure. In the following example log extract, the OS is out of memory, and the OOM-killer starts. To resolve this error, stop the process that consumes the most memory.
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Google Groups
groups.google.com › g › consul-tool › c › qLSxgcmPmEs › m › dbKentx8MwAJ
AWS Failed Instance Status Checks on all 3 Consul-backed Vault EC2 Instances
In AWS these seem to be caused by brief periods of heavy packet loss and/or CPU exhaustion on small instance types, leading them to not meet the soft real-time requirements for Serf's probes. The change will add more independent confirmations before a node is declared dead, but in a way that ...