Public Cloud Flexible Engine

Volume Backup Service (VBS) program and easily save your data disks

VBS provides snapshot-based protection for Elastic Volume Service (EVS) disks in the public cloud

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VBS provides online one-click backup and restoration for EVS disks, such as system and data disks of ECSs, allowing you to leverage another layer of security. If an Elastic Volume Service (EVS) disk of an ECS is faulty or logic errors occur on data, you can use the backups to quickly restore data.

VBS provides disk backup services. A web-based management console is provided for you to back up your EVS disks.
VBS provides the following functions:

  • EVS disk-level backup service
  • Manual backup service
  • Automatic backup service
  • Backup task status query
  • Online incremental backup for EVS disks
  • EVS disk creation using data backup
  • Storage type is SATA supported by OBS.



VBS supports 99.999999999% data durability.


VBS supports two backup methods, manual backup and automatic backup. At the same time VBS supports two restoration methods, reverting an EVS disk to its original state and creating an EVS disk with backup data.


VBS applies to the following scenarios:

  • Improve data reliability:

VBS can be used to back up EVS disks to improve data reliability and prevent data loss. 

  • Prevent logic errors:

If logic errors occur on data or data is infected with viruses, you can use VBS backups to revert the data to its original state or the state before virus infection.


  • Maximum 360 backup sets for each tenant.
  • Each EVS disk of a tenant supports up to 20 backup sets.
  • Total 200T for each tenant.

Note: All VBS backups of a tenant can be stored only in one OBS bucket. Each copy of backup is splitted and stored as 4 MB files. A bucket supports a maximum of 50 Million backup files with a total capacity of 200 TB. Actually, a bucket of OBS supports more than 50 Million files. However, if the number of files exceeds 50 Million, the OBS storage performance deteriorates.

  • Maximum 5 concurrent VBS backup operations executing at one time, including create backup, delete backup and rollback. More operation will be suspended.

Note: The EVS disk quota is required for creating VBS backups. Therefore, you must ensure that the EVS disk quota is sufficient before creating VBS backups.

  • Example 1, assume one tenant has 80 EVS quota, and he already have 76 EVS disks. This tenant only can create 4 new VBS backup tasks. If this tenant creates 5 concurrent VBS backup operation at one times,then only 4 VBS backup tasks will execute concurrently and the rest one will failed.
  • Example 2, assume one tenant has 80 EVS quota, he already have 70 EVS disks and there are 1 VBS rollback task and 1 VBS delete task executing. Then, this tenant could only create maximum 10 VBS backup tasks, however, only 3 concurrent VBS backup tasks are running, the rest 7 new created backup tasks are waiting for execute.

Automated Backup

To improve ease-of-use, Volume Backup Service provides the policy-driven automatic backup feature, Auto Backup. With Auto Backup, tenants can associate a self-defined policy with one or more Elastic Volume Service disks. Then based on the backup policy, Volume Backup Service automatically backs up the Elastic Volume Service disks at specified intervals, eliminating the need for user intervention in backup operations.

Tenants can set the following parameters of a backup policy: backup interval, backup start time, retained number of backups, whether to enable the policy, and whether to retain the first backup of the current month. A tenant can own a maximum of 10 Auto Backup policies. The backup interval ranges from 1 to 14 days. The backup start time is on the hour, from 0:00 to 23:00. A minimum of two backups must be saved, and a maximum of 14 backups can be saved. And the maximum retained number of backups could by modified by system maintenance engineer.

After creating a backup policy, tenants can associate one or more Elastic Volume Service disks with the policy. Then Volume Backup Service periodically backs up the Elastic Volume Service disks and deletes expired backups.

  1. The tenant defines an Auto Backup policy in the VBS Console. Then the tenant associates the backup policy with the EVS disks that need to be backed up.
  2. The VBS Console invokes the Auto Backup API.
  3. The Auto Backup job invokes necessary VBS APIs to back up EVS disks at the tenant-configured backup time.
  4. VBS invokes necessary Cinder APIs to execute the backup job.
  5. Cinder invokes backup software driver to execute the backup job.
  6. From the production storage, backup software obtains the EVS disk data that needs to be backed up.
  7. Backup software stores backup data into backup storage.

  1. The tenant selects a backup of the EVS disk to be restored in the VBS Console.
  2. The VBS Console invokes necessary VBS APIs to execute the restoration job.
  3. VBS invokes necessary Cinder APIs to execute the restoration job.
  4. Cinder invokes backup software driver to execute the restoration job.
  5. Backup software obtains EVS disk backup data from backup storage.
  6. Backup software restores backup data to the production storage.