Create and activate a replication pair - Elastic Compute Service

If you want to implement disaster recovery for a single disk, you can create and activate a replication pair that consists of the disk and another disk in a different region or in a different zone within the same region. This way, data on one disk can be asynchronously replicated to another disk across regions or across zones within the same region for disaster recovery. This topic describes how to create and activate a replication pair.

Prerequisites

The source disk (primary disk) from which to replicate data and the destination disk (secondary disk) to which to replicate data are created. The disks meet the following requirements:

The primary and secondary disks are Enterprise SSDs (ESSDs) or ESSD AutoPL disks that are not being extended or changed.
The primary and secondary disks belong to the same category and have the same performance level and capacity.
The primary and secondary disks do not reside in the same zone.
The secondary disk is in the Unattached state.
Note
The async replication feature replicates data from the primary disk to the secondary disk. To ensure successful replication, the secondary disk must be read-only.
(Recommended) A snapshot is created for the secondary disk to back up disk data. For information about how to create snapshots of disks to back up disk data, see Create a snapshot.
Important
The async replication feature replicates data from the primary disk to the secondary disk, and the replicated data overwrites the original data on the secondary disk. This operation is irreversible. We recommend that you create a snapshot for the secondary disk to back up disk data. You are charged for the created snapshot. For information about the billing of snapshots, see Snapshots.

Procedure

Log on to the Elastic Block Storage (EBS) console.
Note
The first time you log on to the EBS console, you must create a service-linked role for EBS as prompted. For more information, see Service-linked role for EBS.
In the left-side navigation pane, choose Enterprise-level Features > Async Replication.
In the top navigation bar, select the region and resource group to which the resource belongs.

Create a replication pair.

Click the Primary Site or Secondary Site tab and then click Create Replication Pair.

On the page that appears, configure the parameters and follow the on-screen instructions to complete the payment.

The following table describes the parameters.

Parameter	Description
Billing Method	Select a billing method. The subscription and pay-as-you-go billing methods are supported.
Region and Zone	Select the region and zone in which the primary disk resides.
Disk	Select the ID of the primary disk.
Service-linked Role	By default, a service-linked role is created for EBS.
Disaster Recovery Region and Zone	Select the region and zone in which the secondary disk resides. Cross-zone disaster recovery: Select the same region as the primary disk and a different zone from the primary disk. Cross-region disaster recovery: Select a different region from the primary disk.
Destination Disk	Select the ID of the secondary disk. The secondary disk must have the same specifications and capacity as the primary disk.
Replication Pair Name	Enter a name for the replication pair, which is used to identify the replication pair.
Description	Enter a description for the replication pair, which is used to identify the replication pair.
Bandwidth	This parameter is available and required only when you create a subscription replication pair. Select a bandwidth value for async replication based on the amount of data in your business. A greater bandwidth value indicates a higher rate at which data is asynchronously replicated.
Subscription Duration	This parameter is available and required only when you create a subscription replication pair. Select a subscription duration for the replication pair and optionally select Auto-renewal.

Note

After the replication pair is created, you can go to the replication pair list and click Modify in the Actions column that corresponds to the replication pair to change the name or description of the replication pair based on your business requirements.

Activate the replication pair.
1. In the replication pair list, find the replication pair that you created and click Activate in the Actions column.
2. In the Activate Replication Pair dialog box, activate the replication pair.
  1. Click Create Snapshot to create a snapshot for the secondary disk to back up disk data.
    Important
    After the replication pair is activated, data stored on the secondary disk is overwritten. To prevent data loss, we recommend that you create a snapshot for the secondary disk to back up disk data before you activate the replication pair. If you already created a snapshot for the secondary disk, you do not need to create another snapshot for the disk.
  2. Choose an activation method based on your business requirements.
    - One-time manual synchronization: Click Copy Data to immediately initiate a data replication. After the data replication is complete, the status of the replication pair changes to Stopped. You can click Copy Data to initiate an immediate data replication based on your business requirements.
      Note
      To click Copy Data, the replication pair must be in the Created, One-time Syncing, or Stopped state.
    - Automatic synchronization: Click Confirm to allow the system to automatically replicate disk data at an interval of 15 minutes. The interval is defined by the recovery point objective (RPO).
      Note
      To click Confirm, the replication pair must be in the Created, Syncing, Normal, or Stopped state.
    When the status of the replication pair changes to Normal, the async replication feature is enabled and the initial synchronization of disk data is complete. Then, the system automatically replicates data from the primary disk to the secondary disk at an interval of 15 minutes for geo-disaster recovery.