Updated on 2025-08-05 GMT+08:00

Overview

What Is a Backup?

A backup is a copy of a particular chunk of data and is usually stored elsewhere so that it may be used to restore the original data in the event of data loss. It can be generated either manually by a one-off backup task or automatically by a periodic backup task.

A one-off backup task is manually created and is executed only once. Periodic backup tasks are automatically executed based on a user-defined backup policy.

  • A one-off backup is named manualbk_xxxx and can be user- or system-defined.
  • A periodic backup is automatically named autobk_xxxx by CBR.

Cloud Backup Types

There are the following types of backups:

  • Cloud server backup: uses the consistency snapshot technology to protect data for ECSs and BMSs. Backups of non-database servers are server backups, and those of database servers are database server backups.
  • Cloud disk backup: provides snapshot-based data protection for EVS disks.
  • SFS Turbo backup: protects data for SFS Turbo file systems.
  • Desktop backup: protects data for Workspace desktops.

Backup Mechanism

CBR in-cloud backup offers block-level backup. The first backup is a full backup of all used data blocks. For example, if a disk size is 100 GB and 40 GB has been used, only the 40 GB is backed up. An incremental backup backs up only the data changed since the last backup to save the storage space and backup time.

When a backup is deleted, data blocks that are referenced by other backups will not be deleted, ensuring that these other backups can still be used for restoration. Both a full backup and an incremental backup can be used to restore data to a given backup point in time.

When creating a backup for a disk, CBR also creates a snapshot for it. CBR keeps only the latest snapshot. Every time it creates a new snapshot, it deletes the old snapshot.

CBR stores backups in OBS to ensure data security.

Backup Options

CBR supports one-off backup and periodic backup. A one-off backup task is manually created and is executed only once. Periodic backup tasks are automatically executed based on a user-defined backup policy.

Table 1 compares the two backup options.

Table 1 One-off backup and periodic backup

Item

One-Off Backup

Periodic Backup

Backup policy

Not required

Required

Number of backup tasks

One manual backup task

Periodic tasks triggered by a preset backup policy

Backup name

User-defined backup name, which is manualbk_xxxx by default

System-assigned backup name, which is autobk_xxxx by default

Backup mode

The first backup is a full backup and subsequent backups are incremental.

The first backup is a full backup and subsequent backups are incremental.

Application scenario

A one-off backup is usually performed before an OS or application is patched or upgraded. The backup can be used for restoration if the patching or upgrade fails.

Periodic backups are performed as part of routine maintenance. The latest backup can be used to restore data in the event of an unexpected failure or data loss.

You can also use the two backup options together if needed. For example, you can associate resources with a vault and apply a backup policy to the vault to execute periodic backup for all the resources in the vault. Additionally, you can perform a one-off backup for the most important resources to enhance data security. Figure 1 shows the use of the two backup options.

Theoretically, you can create as many backups for a resource as needed. There is no limit to the number of backups you can create for a resource.

Figure 1 Use of the two backup options

Billing

  • You are billed for the storage space and the data traffic generated if backup replication is used. Pricing of the storage space varies with vault types. Backups are stored in vaults, and no additional fees are incurred.
  • If backups are replicated to another region, the source region is charged for the traffic used for cross-region replication.
  • For more information, see CBR Pricing Details.

Supported Operations

You can perform the following operations.

Table 2 Operations supported by CBR

Operation

Description

Viewing a backup

In the backup list, you can set search criteria to filter backups and view their details. The results contain backup tasks that are running or have completed.

Sharing a backup

You can share a server or disk backup with projects of other accounts. Shared backups can be used to create servers or disks.

Deleting a backup

You can delete unwanted backups to reduce space usage and costs.

Replicating a backup across regions

Cross-region replication of server backup vaults and SFS Turbo backup vaults allows you to replicate backups from one region to another.