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 named autobk_xxxx by CBR.

Cloud Backup Types

There are the following types of backups:

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

**Table 1** Differences among the backup types
Item	Cloud Server Backup	Cloud Disk Backup	SFS Turbo Backup	Desktop Backup
What to back up	All disks (system and data disks) on a server or part of disks and cloud servers (with applications)	One or more specific disks (system or data disks)	SFS Turbo file systems	Entire Workspace desktop systems, including all disks
When to use	You want to back up entire cloud servers.	You want to back up only data disks.	You want to back up entire SFS Turbo file systems.	You want to back up entire Workspace desktops.
Advantages	All disks on a server are backed up at a time.	Only data of specific disks is backed up, which costs less than backing up an entire server.	File system data and their backups are stored separately, and the backups can be used to create new file systems.	Desktop data and their backups are stored separately, and the backups can be used to create new desktops.

Backup Mechanism

CBR in-cloud backup offers block-level backup. The first backup is a full backup and backs up all used data blocks. For example, if a disk size is 100 GB and 40 GB has been used, only the 40 GB of data 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 will not be deleted if they are depended on by other backups, ensuring that 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 of a disk, CBR also creates a snapshot for it. CBR keeps only the latest snapshot. Every time it creates a new snapshot during backup, 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 2 compares the two backup options.

**Table 2** 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 the consecutive backups are incremental.	The first backup is a full backup and the consecutive backups are incremental.
Application scenario	Executed before patching or upgrading the OS or upgrading an application. A one-off backup can be used for restoration if the patching or upgrading fails.	Executed for routine maintenance. The latest backup can be used for restoration if an unexpected failure or data loss occurs.

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. This number is not limited.

Figure 1 Use of the two backup options
Click to enlarge

Supported Operations

You can perform the following operations.

**Table 3**
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	CBR enables you to replicate backups of server backup vaults, SFS Turbo backup vaults, and hybrid cloud backup vaults from one region to another.