Cross-Region Replication Across Accounts
Scenarios
Cross-region replication across accounts is to replicate data from a source bucket in one region of an account to a destination bucket in another region of another account.
Replication scope: files, folders, object lists, objects with specified prefix, or specified URL lists
Replicable object data: object name, metadata (object content, size, last modification time, creator, version number, and user-defined metadata), ACL (supported by obsutil), and storage class

Cross-region replication across accounts applies to the following scenarios:
- Regulatory compliance
OBS stores data across AZs that are relatively far apart from each other, but regulatory compliance may require further distances. Cross-region replication enables you to meet regulatory requirements.
- Low latency
The same OBS resources may need to be accessed from different locations. To minimize the access latency, you can use cross-region replication to create object copies in the nearest region.
- Data replication
You want to migrate data stored in OBS to the data center in another region.
- Data backup and disaster recovery
You want to create explicit backups for all data written to OBS in the data center of another region to ensure data remains available if there is any damage.
- Ease of maintenance
You have compute clusters used to analyze the same group of objects in two different OBS regions and may need to maintain object copies in these two regions.

OBS helps you replicate your service data stored in OBS to a specified region, but Huawei Cloud has no access to your data. You need to ensure the legal compliance of your use of OBS on your own. If your replication involves cross-border transfer, ensure that your use complies with relevant laws and regulations.
Constraints
The following are constraints on migrating data using Object Storage Migration Service (OMS):
Item |
Description |
---|---|
Objects with multiple versions |
By default, OMS migrates only the latest version of objects in source buckets. |
Storage class of destination buckets |
The storage class of destination buckets can be Standard, Infrequent Access, Archive, or Deep Archive. |
Migration network |
Migrations over the Internet or intranets are supported. Migrations over private lines are not supported. |
Metadata migration |
Only Chinese characters, English characters, digits, and hyphens (-) can be migrated. Other characters cannot be migrated.
Chinese punctuation marks cannot be URL-encoded during the migration. If metadata contains Chinese punctuation marks, the metadata and the corresponding object will fail to be migrated.
|
Migration scope |
A single migration task or migration task group can only migrate data of one bucket. If data of multiple buckets needs to be migrated, you need to create multiple tasks or task groups. |
Symbolic links |
Symbolic link files cannot be migrated. Symbolic link files will be recorded as failed, and the migration task will also be marked as failed. Other files can be migrated normally. If the source contains symbolic links, you need to enter the actual file path. |
Migration of object ACLs |
OMS cannot migrate object ACLs. |
Migration speed |
Generally, OMS can migrate 10 TB to 20 TB of data per day. For higher migration efficiency, you are advised to use storage migration workflows on MgC. MgC allows you to migrate data using dedicated, scalable migration clusters and up to 20 Gbit/s of bandwidth. However, the speed depends on the number and size of source objects, bandwidth, and transmission distance over the Internet between the source and destination buckets. You are advised to create a migration task to test the migration speed. The maximum migration speed is five times the average speed of a single task because up to five tasks can be executed concurrently in a region by default. If you need to define a higher number of concurrent tasks, you can create a storage migration workflow on MgC. |
Archived data |
You need to restore archived data before the migration. Note that when there is archived data to be migrated, you need to:
|
Migration tasks |
A maximum of five concurrent migration tasks are allowed for your account per region.
NOTE:
If your destination regions are CN North-Beijing1 and CN South-Guangzhou, you can run up to 10 migration tasks concurrently. |
A maximum of 1,000,000 migration tasks can be created in your account per region within a 24-hour period. |
|
Migration Task Groups |
A maximum of five concurrent migration task groups are allowed for your account per region.
NOTE:
If your destination regions are CN North-Beijing1 and CN South-Guangzhou, you can run up to 10 migration task groups concurrently. |
Synchronization tasks |
Synchronization tasks share quotas with migration tasks and migration task groups, but enjoy a higher priority. A maximum of five concurrent synchronization tasks are allowed for your account per region. |
Object list files |
|
URL list files |
|
Failed object list files |
A maximum of 100,000 failed objects can be recorded in a list file.
NOTE:
If more than 100,000 objects fail to be migrated in a migration task, you are advised to rectify the fault based on the existing failed object list and perform the migration again. |
Billing for Cross-Region Replication Across Accounts
- When you use the OMS console or APIs to migrate data, OBS APIs of the source and destination ends are invoked to upload and download data. You will be billed for the API requests and data download traffic. For details, see OMS Billing. In addition, you will be billed for storing the objects in the destination bucket. For details, see Storage Costs.
- When you use obsutil to replicate data across regions, you will be billed for requests, traffic, and storage. For details, see Table 2.
Table 2 Billing for cross-region replication Action
Billing Item
Description
Replicate data across regions
Requests
You are billed for the number of successfully replicated objects. Successfully replicating one object creates a copy request. For details, see Copying Objects.
To learn about the request billing, see Requests.
Data transfer
You are billed for the amount of data transferred from one region to another.
If objects are encrypted using server-side encryption, the cost of their cross-region replication traffic is calculated based on the length of the plaintext for SSE-KMS and SSE-OBS.
Storage space
Storage space occupied by objects stored in the destination bucket.
If you have specified another storage class for object copies in the destination bucket, these copies are billed based on the new storage class.
If objects are encrypted using server-side encryption, their storage cost is calculated based on the length of the ciphertext.
Synchronize existing objects
Requests
You are billed for the number of existing objects that are successfully replicated to the destination bucket.
With synchronization of existing objects enabled, OBS synchronously replicates the objects that already exist in the bucket before a cross-region replication rule is created to the destination bucket.
Data transfer
You are billed for the traffic generated when OBS synchronizes objects across regions.
If historical objects are encrypted using server-side encryption, the cost of their cross-region replication traffic is calculated based on the length of the plaintext for SSE-KMS and SSE-OBS.
Storage space
Storage space occupied by objects stored in the destination bucket.
If you have specified another storage class for object copies in the destination bucket, these copies are billed based on the new storage class.
If historical objects are encrypted using server-side encryption, their storage cost is calculated based on the length of the ciphertext.
Prerequisites
- A source bucket has been created in a region of an account.
- A destination bucket has been created in another region of another account. To create a bucket, see Creating a Bucket.
- When obsutil is used to replicate objects across accounts and regions, the version of the source bucket is 3.0 or later, and cross-region replication is available in the region of the source bucket. For details about the support for cross-region replication in each region, search for "cross-region replication" on the Function Overview page.
Cross-Region Replication Across Accounts
You can use the OMS console or APIs to migrate data across accounts and regions, or use obsutil to replicate data across accounts and regions.

OMS does not automatically migrate data. That is, data changes in the source bucket will not be automatically synchronized to the destination bucket. After data in the source bucket is modified, you need to execute the migration task again to synchronize the incremental data in the source bucket to the destination bucket.
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