Last updated: 2020-02-18 16:34:06

Thank you for using Tencent Cloud Block Storage!

Cloud Block Storage (CBS) is a highly available, highly reliable, low-cost, customizable network block storage device.

Users can use the APIs described in this document to perform operations on cloud disks and snapshots, such as creating an elastic cloud disk, creating a snapshot, or rolling back a snapshot. For more information on supported operations, please see API Overview.

Before using these APIs, please make sure that you have a thorough understanding of CBS Product Overview.


To help you get familiar with CBS and snapshot services more quickly, we provide the definitions of some commonly used terms in the following table:

Term Full Name Description
CBS Cloud Block Storage This refers to distributed block storage independently developed by Tencent Cloud and called Could Storage for short. For more information, please see CBS Product Overview. It includes cloud disk purchased with CVM and elastic cloud disk purchased independently.
Elastic cloud block storage Elastic Cloud Block Storage A cloud disk, also known as elastic cloud disk, that is not purchased along with a CVM (purchased separately), with an independent lifecycle (billing cycle). It can be mounted and unmounted to different CVMs (cannot be mounted simultaneously on multiple CVMs).
Snapshot Cloud Disk Snapshot Used to save a copy of a cloud disk at a certain point. You can use the snapshot to restore the cloud disk to the point when the snapshot was created

Definitions of input and output parameters

  • Limit and Offset

    These parameters are used for paging control. "Limit" indicates the maximum number of entries returned at a time, and "Offset" is the offset value. If the number of results exceeds the Limit, the number of returned results equals the value of Limit.

    For example, if Offset=0&Limit=20, the 0st to 20th entries are returned; if Offset=20&Limit=20, the 20th to 40th entries are returned; if Offset=40&Limit=20, the 40th to 60th entries are returned, and so on.

  • Ids.N

    Formats for inputting multiple parameters at a time. Multiple parameters in such a format can be input at the same time. For example:


    And so on (with subscripts starting with 0).

Getting Started with APIs

To use an elastic cloud disk via APIs, you need to complete the following three steps:

  1. Create an elastic cloud disk: You can use the API CreateDisks (create elastic cloud disk) to create one or more elastic cloud disks.
  2. Mount the elastic cloud disk to the specified CVM: After the elastic cloud disk is created, use the API AttachDisks (Mount Elastic Cloud Disk) to mount it to the specified CVM. Note: The term "mount" here refers to assigning the elastic cloud disk to the specified CVM, similar to a hot-plug of a disk to the server.
  3. Log in to the CVM to initialize the elastic cloud disk: When using the new elastic cloud disk for the first time, you need to perform a series of operations such as partitioning and formatting. Data Disk Mounting, Partitioning and Formatting on Linux System. Note: For Linux system, partitioning is not necessary. You can skip the partitioning process and directly proceed to the formatting.

To use cloud disk snapshots via APIs, you need to complete the following two steps:

  1. Create a cloud disk snapshot: You can use the API CreateSnapshot (create snapshot) to create a snapshot for the specified cloud disk.
  2. Roll back the cloud disk snapshot: If necessary, you can use the API ApplySnapshot (roll back snapshot) to roll back the snapshot to the specified cloud disk.

Use Limits

For restrictions on the usage of CBS and snapshot, please see CBS Usage Restrictions. For restrictions on specific parameters, please see the descriptions of output parameters in the related API documentation.