Operational Checklist: Migrating Node Hosting to Meet EU Sovereignty Requirements

Hook: The compliance pressure is real — here’s an actionable runbook

If you run blockchain nodes or host customer wallets for EU customers, you’re facing a tightening regulatory landscape in 2026: data residency mandates, sovereign assurances, and stricter audit requirements. Migrating to the AWS European Sovereign Cloud can meet many of these demands — but this is an operational migration, not a marketing checkbox. Below is a concrete, step-by-step migration plan and runbook designed for infra teams tasked with moving nodes and customer data into AWS EU while preserving uptime, security, and auditability.

Why migrate now (2026 context)

Late 2025 and early 2026 saw rapid adoption of EU-focused cloud guarantees after AWS launched the European Sovereign Cloud (January 2026). Regulators and enterprise customers now expect:

• Physical and logical separation of data within the EU
• Sovereign assurances and legal protections limiting non-EU access
• Stronger controls over key management and incident response

Concurrently, frameworks like NIS2 and financial requirements under DORA press firms running critical crypto infrastructure to demonstrate robust controls. For infra teams, the migration must protect node consensus, nonce/sequence integrity, key custody, and legal hold obligations.

Overview: The migration plan at a glance

This runbook is organized into eight practical phases. Each phase has tactical tasks and success criteria you can check off.

1. Discovery & Inventory
2. Risk Assessment & Compliance Mapping
3. Design & Architecture (AWS EU sovereign alignment)
4. Pilot: dry-run node relocation
5. Production migration (data transfer & cutover)
6. Validation & post-migration monitoring
7. Legal hold & audit evidence preservation
8. Decommission & retention policy enforcement

Phase 1 — Discovery & Inventory (Essential inputs)

Build a complete picture before touching production.

• Node catalogue: Enumerate full/archival/validator/RPC nodes by chain, region, version, and hardware profile.
• Data inventory: On-disk blockchain databases, snapshots, wallet/customer PII, telemetry logs, backups, and secrets.
• Stateful dependencies: HSMs, KMS keys, external signer services, CA certs, load balancers, NAT/gateway IPs.
• Operational runbooks: Current backup retention, snapshot cadence, and RTO/RPO for each service.

Deliverable: a CSV/CMDB export with node_id, chain, role, storage_gb, inbound_ips, outbound_peers, and compliance_label (e.g., EU-only/customer-data).

Phase 2 — Risk Assessment & Compliance Mapping

Map every data element to legal requirements and risk controls.

• Classify customer data vs. chain state. Customer data (wallet metadata, KYC) typically triggers stricter residency needs.
• Check whether any node data is subject to legal holds or ongoing investigations.
• Identify keys that cannot leave a jurisdiction — plan EKM/HSM architecture in AWS EU or maintain on-prem HSM with secure connectivity.

Success criteria: risk register with mitigation plans for cross-border data flows, SLA impacts, and key custody constraints.

Phase 3 — Design & Architecture: AWS EU sovereign alignment

Design for sovereignty, not just co-location. Key architectural patterns:

• Region selection: Choose AWS EU Sovereign region(s) that provide physical separation and legal assurances. Use only EU sovereign zones for workloads and logs tied to EU-categorized data.
• Network controls: Set up dedicated VPCs, strict egress controls, and VPC endpoints. Use AWS PrivateLink for managed services to avoid public internet egress.
• Key management: Use AWS CloudHSM or AWS KMS with an External Key Manager (EKM) located in the EU, or use customer-managed HSM appliances supporting FIPS 140-3.
• Immutable storage: S3 Object Lock (WORM) and EBS snapshot retention policies for legal hold.
• Isolation: Use separate accounts/organizational units for EU-sovereign workloads and use SCPs to prevent resource creation outside EU boundaries.

Architecture deliverable: a diagram showing account structure, network flow, key stores, and data stores annotated with compliance controls.

Phase 4 — Pilot: dry-run node relocation

Test early with a non-critical node or a read-only archive node. The goal is to validate data transfer methods, time-to-sync, and monitoring.

1. Provision a target instance type in AWS EU with matching storage (GP3 or NVMe as needed).
2. Create KMS/HSM keys in EU and configure VM to use EU KMS for disk encryption.
3. Transfer a recent snapshot: options below (choose one):

Data transfer methods

• AWS DataSync: good for continuous large-volume transfers over AWS Direct Connect / VPN; supports EBS, NFS, S3.
• rsync over encrypted tunnel (VPN/Direct Connect): simple for incremental deltas; ensure you throttle to avoid bandwidth spikes.
• AWS Snowball Edge: recommended if you must move multiple TBs/PBs of archive data and have limited WAN bandwidth.
• S3 snapshot + restore: Upload compressed DB snapshot to EU S3 (Object Lock enabled) and restore on target instance.

Pilot success criteria: node reaches chain head within expected sync time, RPC tests pass, and monitoring metrics match baseline (block height, response percentiles).

Phase 5 — Production migration (data transfer & cutover)

Schedule migrations during low-traffic windows. Maintain read-only or warm-hot replicas during cutover for minimum disruption.

1. Notify stakeholders and list rollback windows.
2. Create immutable snapshots (source) and preserve checksum manifests for every transferred artifact.
3. Perform initial bulk transfer (S3/DataSync/Snowball). Verify checksum and metadata integrity.
4. Perform incremental sync: use rsync or DataSync continuous replication to catch up changes since bulk transfer.
5. Switch traffic via DNS / load balancer after final sync. Use short TTLs to accelerate rollback if needed.
6. Quarantine source for legal hold if required (see Phase 7).

Specific node relocation actions (example for Ethereum geth full node):

1. Stop geth on source: systemctl stop geth or docker stop geth.
2. Snapshot disk: create EBS snapshot or filesystem snapshot and export.
3. Transfer snapshot to AWS EU and restore to target volume.
4. Start geth with flags tuned for production: set correct --datadir, --cache, and RPC CORS/hosts.
5. Validate by comparing latest block hash and chain head timestamp between source and target using JSON-RPC calls.

Phase 6 — Validation & post-migration monitoring

Validation testing must be both functional and compliance-oriented.

• Functional checks: block height parity, consensus peer count, pending transactions, RPC throughput and p99 latency.
• Security checks: verify KMS/HSM key usage, ensure no secrets were inadvertently transferred, validate IAM policies and SCPs.
• Observability: ensure CloudWatch logs and metrics are retained in EU accounts. Forward chain telemetry to EU-resident observability stack (Prometheus/Grafana inside AWS EU or managed observability with EU-only endpoints).
• Performance baselines: compare disk IO, CPU, memory, and network metrics to pre-migration baselines. Tune instance types if needed.

Automated validation scripts (examples):

# sample check (bash pseudo)
JSON_RPC="https://eu-node.example.com"
headHash=$(curl -s -X POST $JSON_RPC -d '{"jsonrpc":"2.0","method":"eth_getBlockByNumber","params":["latest", false],"id":1}' | jq -r '.result.hash')
echo "Head hash: $headHash"
# Compare with a reference node

Phase 7 — Legal hold, retention, and audit evidence

Legal obligations are a central driver of sovereignty migrations. Implement defensible preservation and audit trails.

• Snapshot retention: Keep source snapshots immutable for the legal hold period. Use S3 Object Lock or EBS snapshot policies to prevent deletion.
• Access logs: Enable CloudTrail in all involved accounts and direct logs to an EU-only S3 bucket with Object Lock and restricted access.
• Chain-of-custody manifests: For each transferred artifact, produce a manifest: checksums (SHA256), transfer timestamps, actor IDs, and transfer method metadata.
• Forensic readiness: Keep a frozen copy of binaries / node software versions and system packages to enable future reproduction of the environment.

Strong legal advice: treat preserved snapshots and manifests as potential evidence — avoid destructive tests on these artifacts.

Phase 8 — Decommission & retention enforcement

Decommission sources only after legal holds expire and you have independent verification.

• Apply a staged deletion policy: quarantine & monitor for 30–90 days, then remove network access, then delete after all holds lapse.
• Update CMDB and inventory to reflect the new EU-resident state.
• Run an internal compliance audit: verify KMS/EKM usage, access controls, and logging are functioning as designed.

Operational controls: Keys, signers, and validators

One of the highest-risk items in any node relocation is key management. Practical options:

• Transfer keys to AWS CloudHSM / KMS EKM (in-EU): Best for operations who can legally move keys to EU-managed HSMs.
• Keep keys on-prem and use remote signing: Run an HSM on-prem and implement a secure signing API accessed via encrypted tunnel (mTLS, mutual TLS + signed requests) from EU nodes.
• Third-party custody: Consider regulated custody providers with EU sovereign assurances for high-value assets.

Operational note: always rotate keys after migration and record rotation events in the manifest.

Network and latency considerations for RPC & validators

Relocating nodes can change latency to peers and clients. Operational steps:

• Benchmark peer topology pre-migration. If peer latency increases for validator nodes, consider retaining a small set of validator peers on-prem or in low-latency colocation with EU peers.
• Use AWS Global Accelerator or regional load balancers inside the EU to reduce client latency.
• For high-availability RPC layers, deploy multi-AZ replicas inside the EU sovereign region and use DNS failover with health checks.

Rollback and contingency planning

Every migration must include a clear rollback path. Key elements:

• Preserve bootable snapshots of source systems and verify restores before cutover.
• Maintain DNS TTLs at 60 seconds or less during cutover for rapid traffic switches.
• Define an RTO (time to rollback) and RPO (acceptable data loss) per service. If rollback is invoked, capture new snapshots immediately for forensic reasons.

Monitoring & SLA checklist

Post-migration, track these KPIs for at least 30 days:

• Block sync lag and consensus head parity
• RPC p50/p95/p99 latencies
• Successful signature rates (for validators)
• Storage IO and snapshot completion times
• CloudTrail and S3 access logs delivered to EU buckets

Example runbook: Quick operational checklist (one-page)

1. Inventory complete? (yes/no)
2. Legal holds & compliance mapping done? (yes/no)
3. Target AWS EU accounts & VPCs provisioned? (yes/no)
4. KMS/HSM configured in EU? (yes/no)
5. Initial snapshot created and WORM-protected? (yes/no)
6. Bulk transfer complete & checksum verified? (yes/no)
7. Incremental sync performed; delta size < RPO? (yes/no)
8. Cutover planned with rollback window and notified stakeholders? (yes/no)
9. Post-cutover validation passed? (yes/no)
10. Source quarantined for legal hold (if required)? (yes/no)

Common pitfalls & mitigation

• Pitfall: Incomplete key transfer planning — keys left in non-EU locations. Mitigation: Create a key-mobility plan and coordinate with legal.
• Pitfall: Unsupported node software versions fail to restore. Mitigation: Snapshot full system images and store package manifests.
• Pitfall: Audit logs inadvertently streamed out of EU. Mitigation: Enforce SCPs and block cross-region log exports.

Case study (hypothetical, based on 2026 best practices)

A mid-size Web3 payments provider migrated 18 nodes (mix of validators and RPC gateways) and 120 TB of archival data to the AWS European Sovereign Cloud in Q1 2026. They used Snowball Edge for the initial 100 TB transfer, DataSync for continuous sync, and CloudHSM + EKM for key controls. Total downtime per RPC endpoint averaged 4 minutes thanks to DNS failover, and audit reviewers validated chain-of-custody manifests within 72 hours. The migration reduced their regulator's inquiries on cross-border access and passed a DORA readiness check later that quarter.

Checklist: Essential commands & templates

Use these snippets as starting points; adapt to your infrastructure.

# Create EU KMS key (aws cli pseudo)
aws kms create-key --description "EU sovereign key for node encryption" --region eu-sovereign-1

# Snapshot creation (EBS)
aws ec2 create-snapshot --volume-id vol-1234abcd --description "pre-migration snapshot"

# rsync over ssh (incremental)
rsync -avz --inplace -e 'ssh -i /path/key.pem' /var/lib/geth/ ubuntu@eu-node:/data/geth/

Operational takeaways

• Begin with inventory and legal mapping — you cannot migrate what you haven’t classified.
• Design for sovereign controls (KMS/HSM in EU, Object Lock, account isolation) not just physical locality.
• Use a staged approach: pilot, bulk transfer, incremental sync, cutover, and a monitored validation window.
• Preserve chain-of-custody and immutable snapshots for legal hold and audits.
• Plan key handling early: decide whether keys move to EU HSMs or remain for remote signing.

Closing: Move confidently, document everything

Migrating blockchain nodes and customer data into the AWS European Sovereign Cloud is achievable with disciplined planning and the right operational controls. The combination of EU residency requirements and 2026 regulatory trends makes this migration a priority for many infra teams. Use this runbook as your operational backbone: customize the steps to your chains, node roles, and legal constraints, and prioritize auditability and key custody at every stage.

Call to action

If you need a tailored migration checklist or an automated runbook template for your stack (Ethereum, Solana, Bitcoin, or multi-chain), download our starter templates and checksum manifest generator, or contact our team for a migration audit. Move quicker and stay compliant — plan your AWS EU sovereignty migration with evidence and confidence.

Related Reading

• Partner Massage Scripts for Apologizing and Rebuilding Trust: Therapist-Approved Routines
• When Poor Data Management Costs You Goals: Scouting and Match Prep Failures
• Easing Noise Anxiety in Pets: From Noise-Cancelling Headphones for Owners to Cozy Hiding Spots
• VistaPrint Coupons Decoded: 10 Easy Ways Small Businesses Can Save 30% or More
• Designing a Pizza-Friendly Open Kitchen for a Designer Home or Airbnb