PASSEDcloud / aws_ec2

AWS: EC2 Instance Store Volume Lost After Stop/Start

An EC2 instance with instance store volumes was stopped and started. All ephemeral data lost including application state and temp files.

Pattern

AWS_CLOUD

Expected: AWS_EC2_FAILURE

Severity

HIGH

Confidence

68%

Remediation

Auto-Heal

Test Results

Metric	Expected	Actual
Pattern Recognition	AWS_EC2_FAILURE	AWS_CLOUD
Severity Assessment	HIGH	HIGH
Incident Correlation	N/A	None
Cascade Escalation	N/A	No
Remediation	—	Auto-Heal — Corax resolves autonomously

Scenario Conditions

AWS EC2 m5d.large with instance store NVMe. Instance stopped for maintenance. Instance store data wiped on stop. Application expected persistent data.

Injected Error Messages (1)

AWS EC2 instance store data lost — instance i-000000 (m5d.large) stopped/started, instance store volume empty, application data not persisted to EBS, startup failing: 'data directory empty'

Neural Engine Root Cause Analysis

AWS cloud infrastructure event detected — an EC2 instance may be unreachable or in a stopped state, an RDS database is experiencing issues, a load balancer has unhealthy targets, or a Lambda function is failing. AWS service disruptions can cascade across dependent resources and affect application availability.

Remediation Plan

1. Check the AWS Health Dashboard and Personal Health Dashboard for any active service events. 2. For EC2 issues, check instance status checks (system and instance), review CloudWatch metrics, and check VPC security group rules. 3. For RDS, verify database instance status, check storage and connection limits, and review slow query logs. 4. For ELB issues, check target group health checks and verify backend instances are responding. 5. For Lambda, review CloudWatch Logs for invocation errors and check IAM permissions and VPC connectivity.

Improvements Applied

Pattern classified as AWS_CLOUD (expected AWS_EC2_FAILURE)

Tested: 2026-04-02Monitors: 1 | Incidents: 1Test ID: cmnhnr8vb09belig7asv36i1o