Object & Block Storage Errors
S3 permissions, NFS mounts, quotas, signed URLs and volume attachment.
Understanding Storage errors
Storage errors are dominated by permissions and locality. S3 access denials can come from an IAM policy, a bucket policy, a Block Public Access setting, an ACL or a KMS key policy: five independent layers, all of which must allow the call. Block storage errors are usually about availability zones: a volume can only attach to an instance in the same AZ.
How to debug Storage errors
- For S3 denials, check all five layers: IAM policy, bucket policy, Block Public Access, object ACL and the KMS key policy if the object is encrypted with a customer-managed key.
- Confirm the region and the exact bucket name. A bucket in another region returns a redirect or a permanent error that reads like a permission problem.
- For signed URLs, check the expiry and that the clock on the signing machine is correct. A skewed clock produces URLs that are already expired.
- For NFS stale file handles, remount rather than retrying; the file the handle referred to no longer exists on the server.
- For volume attachment failures, verify the availability zone matches and that the volume is in the
availablestate, not still attached elsewhere.
Tools worth reaching for
aws s3api get-bucket-policyIAM Policy Simulatormount -v / showmount -edf -h / du -shaws ec2 describe-volumes
All 13 Storage errors
- AWS S3: Access Denied on an object encrypted with KMS NewThe bucket policy allows the read but the caller has no permission on the KMS key, so S3 cannot decrypt the object for…
- AWS S3: Bucket does not existSpecified S3 bucket doesn't exist or is in different region.
- AWS S3: SignatureDoesNotMatch NewThe SigV4 signature computed by the client differs from the one S3 computed. Causes: wrong secret key, clock skew…
- AWS: EBS volume not available in AZAn EBS volume cannot be attached to an EC2 instance because they are in different Availability Zones. EBS volumes are…
- Azure Blob: Lease conflictBlob is leased by another client. Cannot modify until lease expires or is released.
- Browser: Storage quota exceededlocalStorage or IndexedDB quota exceeded. Browser has storage limits per origin.
- Ceph: OSD downA Ceph Object Storage Daemon is not running, reducing cluster redundancy and potentially causing degraded performance.
- Google Cloud Storage: Signed URL expiredGCS signed URL has exceeded its expiration time. Need to generate new signed URL.
- Linux: mount error(13): Permission denied (CIFS/SMB) NewThe SMB server rejected the credentials or the requested protocol. Common causes are a domain user given without the…
- NFS: Mount timeoutNFS mount operation timed out. Server unreachable, firewall blocking, or NFS service down.
- NFS: Stale file handleThe NFS client holds a reference to a file or directory that no longer exists on the server, usually after the export…
- S3: Access denied by bucket policyS3 bucket policy explicitly denies access. Need to update bucket policy or IAM permissions.
- S3: Eventual consistency causing read-after-write issuesReading S3 object immediately after write may return old version due to eventual consistency.
Other categories
- AI 35Rate limits, context windows, GPU memory and model-serving failures.
- Ansible 10Unreachable hosts, become passwords, undefined variables and Jinja2 failures.
- API 14Auth headers, payload limits, versioning, idempotency and webhook signatures.
- Apple 10Command line tools, dyld, Homebrew permissions, notarisation and Keychain.
- Auth 11OIDC, SAML, Auth0, Okta, Keycloak, passkeys and MFA failures.
- BigData 11Spark, Kafka, Airflow, Snowflake, Flink and Databricks failures.
- C# 12NuGet restore, null references, EF Core migrations, async deadlocks and Blazor…
- C++ 11Segfaults, linker errors, memory corruption and template deduction failures.
- Caching 10Cache stampedes, stale content, Varnish and CloudFront failures.
- CI/CD 18GitHub Actions, GitLab CI, Jenkins, CircleCI: permissions, runners and…
- Client 21CORS, mixed content, module resolution, memory limits and framework runtime…
- Cloud 25IAM permissions, quotas, service limits and credential failures.
- Dart 10Null safety, pub version solving and build toolchain problems.
- Database 41Connections, deadlocks, constraints, replication and memory limits.
- DNS 10NXDOMAIN, SERVFAIL, timeouts, propagation and delegation problems.
- Docker 27Daemon connectivity, disk space, image pulls, ports and architecture mismatches.
- Elixir 9GenServer timeouts, supervision failures and Mix compilation problems.
- Email 8Delivery failures, relay denial, authentication, SPF, DKIM and DMARC.
- Frontend 23Hydration mismatches, bundler resolution, layout shift and font loading.
- Git 20Merge conflicts, rejected pushes, detached HEAD, LFS and repository corruption.
- Go 19Nil map assignment, concurrent map access, context cancellation and deadlocks.
- GraphQL 13Validation, depth limits, N+1 queries and fragment problems.
- gRPC 10Status codes, deadlines, message limits, TLS and HTTP/2 transport failures.
- HTTP 494xx client errors, 5xx server errors, redirects, headers and protocol problems.
- ICMP 23Destination unreachable, time exceeded, fragmentation needed and redirects.
- Ingress 8404 default backend, missing TLS secrets, IngressClass and path matching.
- Java 19Class loading, dependency resolution, connection pools and JVM version…
- JavaScript 42npm resolution, async pitfalls, hydration, memory limits and runtime type…
- Kubernetes 34CrashLoopBackOff, ImagePullBackOff, OOMKilled, RBAC, scheduling and storage.
- Logging 9Log4j, Logback, Fluentd, Logstash and CloudWatch ingestion problems.
- MessageQueue 14Kafka, RabbitMQ, SQS, NATS and Celery: lag, rebalancing and poison messages.
- Mobile 17Gradle, CocoaPods, Xcode signing, Metro bundler and toolchain mismatches.
- Monitoring 12Prometheus scrapes, Grafana data sources, OpenTelemetry exporters and agent…
- Network 35Refused connections, timeouts, resets, MTU problems and port exhaustion.
- Performance 6GC pauses, thread pool starvation and event loop blocking.
- PHP 11Memory limits, execution timeouts, autoloading, Composer and PDO connections.
- Proxy 17nginx, Envoy, HAProxy, Traefik, Caddy and Cloudflare upstream failures.
- Python 35Imports, virtual environments, encoding, concurrency and dependency conflicts.
- Regex 8Catastrophic backtracking, back references, escaping and engine differences.
- Ruby 11Bundler, migrations, native extensions, encoding and asset compilation.
- Rust 19Borrow checker, ownership moves, trait bounds and lifetime mismatches.
- Scala 6Dependency resolution, binary compatibility and type inference failures.
- Security 25JWT validation, CSRF, OAuth grants, SELinux, SSH host keys and CSP.
- Serverless 11Lambda timeouts, package size limits, VPC networking and cold starts.
- Shell 13Command not found, permissions, quoting, expansion and Makefile syntax.
- Svelte 10Store subscriptions, load functions and server/client boundaries.
- System 26Disk space, systemd units, file descriptors, OOM killer and scheduled jobs.
- Terraform 18State locks, provider auth, drift, dependency cycles and plan-time unknowns.
- Testing 18Jest, pytest, JUnit, Cypress and Playwright: fixtures, snapshots and timeouts.
- TLS 24Untrusted authorities, expiry, hostname mismatch, chains and cipher negotiation.
- TypeScript 19Assignability, missing declarations, strict null checks and generic constraints.
- Virtualization 8VirtualBox, VMware, Hyper-V, WSL, KVM and hypervisor conflicts.
- Web3 7Gas estimation, nonce management and reverted transactions.
- WebAssembly 7Compile errors, memory bounds and host binding mismatches.
- WebServer 10nginx, Apache, IIS and Caddy: binding, permissions, rewrites and TLS.
- Windows 10Installer failures, missing runtimes, update errors and permission problems.