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    Cloud Backup:Select an ECS disaster recovery method

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    Cloud Backup:Select an ECS disaster recovery method

    Last Updated:Oct 15, 2025

    If you do not have special requirements for recovery point objectives (RPOs) or are limited by the operating systems for continuous data replication (CDR), we recommend you use EBS async replication with an RPO of 15 minutes. This way, you do not need to install a client to occupy Elastic Compute Service (ECS) resources, and are not limited by operating systems. The EBS async replication solution is more cost-efficient.

    The following table describes the differences between EBS async replication and CDR.

    Item

    ECS disaster recovery (EBS async replication)

    ECS disaster recovery (CDR)

    Scenarios

    • Disaster recovery that ensures the consistency of virtual machine (VM) groups. If you do not expect intrusions into the system, you can use this replication technology.

    • Large application scale

    • Various operating systems

    • Large data volume

    • Disaster recovery for a single VM. If you do not mind intrusions into the system, you can use this replication technology.

    • A maximum of 10 ECS instances

    • Small application scale

    • Small ECS data volume

    • Operating systems compatible with CDR

    Intrusive to the system

    No

    A client must be installed, which occupies ECS resources.

    Replication implementation

    Data is replicated by using the EBS async replication and snapshot features.

    An agent is installed on the operating system of the protected instance, so that Cloud Backup replicates data written into the disks and sends the data to a gateway in real time. The gateway stores the data in an Object Storage Service (OSS) bucket and then writes the data to the disk at the disaster recovery site.

    Recovery implementation

    Supports only a single recovery point.

    Cloud Backup creates a recovery point by replicating the snapshot to the disaster recovery site.

    Supports multiple recovery points.

    A shadow ECS instance and a gateway server are created for the protected ECS instance at the disaster recovery site. Cloud Backup reads data from the OSS bucket to the shadow ECS instance, writes the data to the ECS instance at the disaster recovery site, and then creates a recovery point based on the snapshot mechanism.

    Consistency group

    Supported

    Not supported

    RPO

    15 minutes

    1 to 5 minutes (the RPO cannot be guaranteed if a large amount of data is written)

    Cost

    • Low

    • Fees of Cloud Backup clients for ECS disaster recovery, disk usage at the disaster recovery site, and replication traffic

    • Slightly high

    • Fees of Cloud Backup clients for ECS disaster recovery, disk usage at the disaster recovery site, replication traffic, and shadow ECS instance

    Maximum replication throughput of a single disk

    100 MB/s

    30 MB/s

    Maximum replication throughput of a single site pair

    No upper limit

    50 MB/s

    Operating system compatibility

    Most operating systems are compatible.

    For more information, see Limits.

    Only some Windows and Linux operating systems are compatible.

    For more information, see Limits.

    Disk type compatibility

    ESSD

    All types

    For more information, see FAQ about ECS disaster recovery.