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PATTERN Cited by 1 source

Snapshot-clone rapid failover

Intent

Achieve sub-minute volume-level DR recovery by pre-provisioning a copy-on-write clone from the latest replication snapshot in the DR region, so failover becomes a traffic redirect rather than a storage rebuild.

Mechanism

  1. Continuous replication (e.g. SnapMirror) delivers snapshots to the DR region at a fixed interval
  2. Scheduled automation (e.g. daily) creates a copy-on-write clone (e.g. FlexClone) from the latest available snapshot
  3. The clone is presented to a pre-staged compute instance (read-only mode)
  4. On DR trigger, application traffic is redirected to the pre-provisioned instance — no storage provisioning needed at failover time

The clone creation is sub-2-minute (metadata-only operation), and because it's done proactively, the actual failover path is even faster — it's purely an application-layer cutover.

Key properties

  • Near-zero additional storage: clone shares blocks with parent via CoW
  • Non-disruptive: clone creation doesn't interrupt ongoing replication
  • Pre-provisioned: eliminates storage-provisioning latency from the failover critical path
  • Bounded RPO: determined by the replication schedule (not the clone refresh schedule)
  • Bounded staleness of read-only view: determined by the clone refresh schedule (e.g. daily)

Trade-offs

Advantage Cost
Sub-15-minute read-only recovery Read-only view may be up to clone-refresh-interval stale
Minimal storage overhead Full read-write still requires SnapMirror break sequence
Replication not interrupted by failover Requires orchestration automation for clone refresh
Works with any snapshot-capable storage Specific to storage systems with CoW clone support

Production reference

S&P Global's Capital IQ platform on Amazon FSx for NetApp ONTAP: SnapMirror at 15-minute intervals + daily FlexClone refresh achieves sub-15-minute read-only failover for a global financial data platform serving strict RTO/RPO requirements.

(Source: sources/2026-07-07-aws-sp-globals-disaster-recovery-fsx-netapp-ontap)

DR tier mapping

This pattern implements a hybrid warm-standby (read-only) + pilot-light (read-write) shape: - The pre-provisioned read-only clone is warm standby (ready to serve immediately) - Full read-write requires the patterns/two-phase-dr-read-then-write orchestration (pilot-light activation)

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