All Products
Search

This Product

    Elastic Compute Service:Create and activate a replication pair

    Document Center

    Elastic Compute Service:Create and activate a replication pair

    Last Updated:May 15, 2026

    Replicate data between two ESSD disks asynchronously every 15 minutes for cross-zone or cross-region disaster recovery.

    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 two disks:

    • Primary disk -- The source disk with your production data.

    • Secondary disk -- The destination disk that stores replicated data.

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

    After activation, the system performs an initial full sync, then replicates changes at regular intervals. The default RPO is 15 minutes. Enable RTC to reduce the RPO to 10 minutes or less. In a disaster, 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, if applicable)

    • 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.

    See Block Storage pricing.

    Prerequisites

    Ensure that you have:

    • Two ESSD or ESSD AutoPL disks with the same capacity and performance level are created.

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

    • The secondary disk is in Unattached state.

    • Neither disk is being resized or modified.

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

    Important

    Activation overwrites all data on the secondary disk with data from the primary disk. This operation is irreversible. Create a snapshot of the secondary disk before activation.

    Create a replication pair

    1. Log on to the EBS console.

      Note

      First-time users must create the required service-linked role when prompted.

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

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

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

    5. Configure the following parameters:

      Parameter

      Description

      Region and Zone

      The primary disk's region and zone.

      Disk

      The primary disk ID.

      Disaster Recovery Region and Zone

      The destination zone. Cross-zone DR: same region, different zone. Cross-region DR: different region.

      Destination Disk

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

      Enable Replication Time Control (RTC)

      Optional. Select Yes to guarantee RPO ≤ 10 minutes. Cross-zone RTC incurs no additional charge; cross-region RTC incurs bandwidth charges. See Async replication overview.

      Risk Disclosure

      Select I am aware of the risks to acknowledge that data on the secondary disk will be overwritten.

      Replication Pair Name

      The replication pair name.

      Description

      Optional. A description for reference.

    6. Complete the payment.

    Activate the replication pair

    Activate the replication pair to start data replication.

    1. In the replication pair list, find 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 if you have not backed up the data.

      2. Choose an activation method:

        • Copy Now -- Performs a single replication, then sets the status to Stopped. Suitable for testing or manual control.

        • OK -- Starts continuous replication with 15-minute RPO (or ≤10 minutes if RTC is enabled). Suitable for production disaster recovery.

    3. Monitor the replication status. The status changes to:

      Status

      Meaning

      Initial Syncing

      Initial synchronization in progress. Displays a progress percentage.

      Normal

      Active and syncing continuously.

      Stopped

      Replication paused.

      When the status reaches Normal, data is being replicated continuously.

    Next steps

    FAQ

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

    The dropdown shows only ESSD or ESSD AutoPL disks with the same capacity and performance level as the primary disk, in unattached state.

    If no disks appear, 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. To use the secondary disk, stop the replication pair first.