Cloud Block Storage

A stable, low-latency, scalable, and persistent block storage service


Tencent Cloud Cloud Block Storage (CBS) provides a persistent block storage service for CVM instances. CBS automatically stores data in multiple redundant copies in an availability zone to eliminate the risk of single points of data failure, providing up to 99.9999999% data reliability. CBS offers cloud disks in multiple types and specifications to achieve stable and low-latency storage performance. CBS can be mounted to or unmounted from instances in the same availability zone, and its storage capacity can be altered in a few minutes, meeting elastic storage requirements. Payment is based on actual usage, and allowing you to enjoy all the above features at a low price point.


Elastic Scalability

One single cloud disk can store up to 16 TB of data, and up to 10 cloud disks (160 TB) can be mounted to one single CVM instance. The storage capacity can be freely configured and scaled as needed to meet the requirements of your business, enabling efficient processing of big data at the terabyte and petabyte levels.

Multiple Storage Types

CBS offers three volume options including HDD cloud disk, premium cloud disk and SSD cloud disk to meet different business storage requirements. SSD cloud disk uses NVMe high-performance SSD, and one single disk is capable of providing 24,000 random IOPS and a throughput of 260 MB/s, making it easy for your business to sustain high-throughput database access.

High Stability and Reliability

Before each storage write request is returned to the user, CBS ensures that the data has already been successfully written to three cross-rack storage nodes. The data replication mechanism of CBS is higher than the industry average, ensuring rapid data migration and recovery in case that any copy fails and achieving up to 99.9999999% data reliability to protect your applications from component failures.

Easy to Use

CBS can be used and managed through simple operations such as creation, mounting, unmounting and deletion, reducing the costs of manual management and deployment.

Snapshot Backup

Data can be backed up by taking point-in-time snapshots of cloud disks to prevent data loss due to tampering or accidental deletion and ensure quick rollbacks in the event of business failure.


CBS provides elastic, efficient and reliable data storage and backup services for CVM instances.

A cloud disk can be freely mounted and unmounted in the same region without the need to shut down or restart the server. Its storage capacity can be configured elastically and scaled on demand. Up to 20 cloud disks can be mounted to one single virtual machine, providing up to 320 TB of storage that fully satisfies the requirements of high-volume file systems in various businesses such as big data, data warehousing and log processing.


Corporate Office Applications

Hardware failures in traditional storage systems can cause serious business interruptions for dozens of hours. CBS efficiently supports hot migration for virtual machines to prevent such type of interruptions in advance. With comprehensive capabilities of data backup, snapshot and data recovery, it is suitable for high-load and core business-critical systems, helping meet the needs of corporate office applications for elastic and reliable large-capacity block storage.

Relational/NoSQL Databases

Core business databases have to sustain intensive access requests during peak application hours, which requires continuous and stable high performance and low latency for the disks. Based on full SSD storage media and distributed architecture, the SSD cloud disk option of CBS features superior performance and high reliability, which helps meet the demanding requirements for performance in SQL scenarios, support high-throughput database requests of the business and satisfy the high IO needs of NoSQL/relational databases with ease.

High-Volume Data Analytics

High-IO storage scenarios of data analytics often require extremely high throughput for the storage system. With excellent multi-thread access performance, CBS can efficiently support Hadoop-Mapreduce and HDFS for processing terabytes or petabytes of data offline, making it ideal for many fields such as data analytics, data mining and business intelligence.


CBS provides two billing options to meet different customer needs: monthly subscription and pay-as-you-go. The monthly subscription mode is an upfront payment (unit: USD/GB * month). A minimum one month purchase is required. It's suitable for businesses with stable and long-term demands. The pay-as-you-go mode is an hourly settlement (unit: USD/GB * hour) that freezes fees for one billing cycle upon purchase. This option enables you to purchase or release resources at any time, making it suitable for business where the demand fluctuates significantly, such as flash sale campaigns on an e-commerce site.

For more information, see Product Pricing.