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    Elastic Compute Service:Create and activate a replication pair

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    Elastic Compute Service:Create and activate a replication pair

    Last Updated:Feb 06, 2026

    Replication pairs enable continuous, asynchronous data replication between two ESSD disks for disaster recovery. Data on the primary disk is automatically replicated to the secondary disk every 15 minutes, protecting against zone or regional failures.

    Quick decision guide

    Use case

    Goal

    Recommended approach

    Protect a single disk within a region

    Near-zero data loss with local redundancy

    Create a cross-zone replication pair

    Protect a single disk across regions

    Regional disaster protection

    Create a cross-region replication pair

    Protect multiple related disks

    Application-consistent failover

    Use a replication pair-consistent group

    How it works

    A replication pair consists of:

    • Primary disk: The source disk containing your production data

    • Secondary disk: The destination disk that receives replicated data

    The disks must be in different zones—either within the same region (cross-zone replication) or in different regions (cross-region replication).

    After activation, the system performs an initial full synchronization, then continuously replicates changes at regular intervals. The default Recovery Point Objective (RPO) is 15 minutes. Enable Replication Time Control (RTC) to reduce the RPO to 10 minutes or less. In a disaster scenario, fail over to the secondary disk with minimal data loss.

    Billing

    Replication pairs use pay-as-you-go billing. Charges include:

    • Replication pair service (based on disk capacity)

    • Snapshot storage (for backup snapshots)

    • RTC bandwidth (if enabled for cross-region replication)

    Note

    Enabling RTC for cross-zone replication within the same region incurs no additional charge. Cross-region replication with RTC enabled incurs additional bandwidth charges.

    Prerequisites

    Before you begin, ensure that you have:

    • Two ESSD or ESSD AutoPL disks with identical capacity and performance level

    • The disks in different zones (same region or different regions)

    • The secondary disk in Unattached state

    • Neither disk undergoing resize or modification

    • (Recommended) A snapshot of the secondary disk to back up existing data

    Important

    When you activate the replication pair, data on the secondary disk is overwritten by data from the primary disk. This operation is irreversible. Create a snapshot of the secondary disk before activation to preserve existing data.

    Create a replication pair

    1. Log on to the EBS console.

      Note

      First-time users must create the required service-linked role when prompted. See Service-linked role for EBS.

    2. In the left navigation pane, choose Enterprise-level Features > Async Replication.

    3. In the top navigation bar, select the region of your primary disk.

    4. On the Primary Site tab, click Create Replication Pair.

    5. Configure the following parameters:

      Parameter

      Description

      Billing Method

      Pay-as-you-go (only supported method)

      Region and Zone

      Region and zone of the primary disk

      Disk

      ID of the primary disk

      Disaster Recovery Region and Zone

      Destination zone. For cross-zone DR: same region, different zone. For cross-region DR: different region.

      Destination Disk

      ID of the secondary disk. Must match the primary disk's capacity and performance level.

      Enable Replication Time Control (RTC)

      Optional. Select Yes to guarantee RPO ≤ 10 minutes using high-quality bandwidth. Cross-zone replication within the same region incurs no additional charge. Cross-region replication incurs additional charges. See Async replication overview.

      Risk Disclosure

      Read the risk disclosure and select I am aware of the risks to acknowledge that data on the secondary disk will be overwritten.

      Replication Pair Name

      Identifier for the replication pair

      Description

      (Optional) Description for reference

    6. Complete the payment process.

    Activate the replication pair

    After creating the replication pair, activate it to start data replication.

    1. In the replication pair list, locate your replication pair and click Activate in the Actions column.

    2. In the Activate Replication Pair dialog box:

      1. (Recommended) Click Create Snapshot to back up the secondary disk.

        Important

        Activation overwrites all data on the secondary disk. Create a snapshot now if you haven't already backed up the data.

      2. Choose an activation method:

        • Copy Data (one-time sync): Performs a single replication, then sets status to Stopped. Use this for testing or manual control scenarios.

        • Confirm (automatic sync): Starts continuous replication with 15-minute RPO (or ≤10 minutes if RTC is enabled). Use this for production disaster recovery.

    3. Monitor the replication status. After activation, the status changes to:

      • Syncing: Initial synchronization in progress

      • Normal: Replication pair is active and syncing continuously

      • Stopped: Replication is paused

    What's next

    FAQ

    Why can't I select a disk in the destination zone?

    The dropdown only shows disks that meet all requirements: ESSD or ESSD AutoPL type, same capacity and performance level as the primary disk, and unattached state.

    If you don't see any disks, create a new ESSD disk in the destination zone with matching specifications and keep it unattached.

    What happens to the secondary disk during replication?

    The secondary disk becomes read-only during active replication. You cannot attach it to an ECS instance or write data to it directly. To use the secondary disk, stop the replication pair first.