Welcome to Tencent Cloud Block Storage (CBS). CBS is a highly available, reliable, economical, and customizable network block storage service. For more information, see Overview. You can use the APIs in this document to perform various operations on cloud disks and snapshots, such as creating elastic cloud disks, creating snapshots, and rolling back snapshots. For supported operations, see API Overview. You need to fully understand the concepts in Overview, Creating Cloud Disks and Price Overview. > Note: *> * All APIs in this section are version 3.0. New CBS APIs added in the future will also be version 3.0. We strongly recommend you use API 3.0. > * Legacy APIs remain available but will not be updated. For documentation of legacy APIs, see CBS API (Legacy). ##Glossary To quickly familiarize you with cloud disk and snapshot services, some common terms are explained in the following table: | Term | Chinese | Description || --- | --- | --- || CBS | CBS | Cloud Block Storage (CBS) is Tencent Cloud’s proprietary distributed block storage service, including cloud disks purchased along with CVM instances and elastic cloud disks purchased separately. For more information, see Overview. || Elastic cloud disk | Elastic cloud disk | An elastic cloud disk is purchased separately rather than along with a CVM instance. It has an independent (billing) lifecycle and can be freely attached and detached across CVM instances. It cannot be attached to multiple CVM instances at the same time though. || Snapshot | Snapshot | A cloud disk snapshot is used to save a copy of the cloud disk at a point in time. You can use the snapshot to restore the cloud disk to the point in time when the snapshot was created. |#### Request and response 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 to the value of Limit.>>For example, if Offset=0&Limit=20, the 0th 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>Format for inputting multiple parameters at a time. The format below indicates that multiple parameters can be input at the same time: > > Ids.0=10.12.243.21&Ids.1=10.11.243.21&Ids.2=10.12.243.21&Ids.3=10.13.243.21...> > and so on (starting from the subscript 0). ## Getting Started with APIs To use an elastic cloud disk through APIs, you need to complete the following three steps: 1. Create an elastic cloud disk by using the CreateDisks API. 2. Attach the elastic cloud disk to the specified CVM instance by using the AttachDisks API. *Note: Attaching here refers to assigning the elastic cloud disk to the specified CVM instance, which is equivalent to hot-plugging a disk to the instance. 3. Log in to the CVM instance to initialize the elastic cloud disk. When using the newly created elastic cloud disk for the first time, you need to perform a series of operations such as partitioning and formatting. For detailed directions, see Initializing Data Disk (Windows CVM) and Initializing Cloud Disk (≥ 2 TB). Note that partitioning is not necessary on Linux, so you can directly format the disk. To use a cloud disk snapshot through APIs, you need to complete the following two steps: 1. Create a snapshot for the specified cloud disk through the CreateSnapshot API. 2. Roll back the cloud disk snapshot as needed to the specified cloud disk through the ApplySnapshot API. ## Limits For the limits of cloud disks and snapshots, see Use Limits. For specific parameter restrictions, see the descriptions of output parameters in the API documentation.