Cloud Block Storage is a highly available, highly reliable, low-cost, and customizable network block device that can be used as a standalone scalable disk for cloud servers. It provides data storage at the data block level and employs a 3-copy distributed mechanism to ensure data reliability for cloud servers. Cloud Block Storage offers five types of disks: premium cloud disk, balanced SSD cloud disk, SSD cloud disk, enhanced SSD cloud disk, and ultra-fast SSD cloud disk. Each disk type has distinct performance, features, and pricing, allowing you to choose based on your application requirements.
Supports and Limits
Currently, Enhanced SSD and ulTra SSD are only available in certain availability zones. They will be supported in more availability zones.
Enhanced SSD is only supported when attached to S5, M5, SA2, and later generation models created after August 1, 2020. Performance cannot be guaranteed when mounted on older generation instances.
ulTra SSD can only be purchased together with Standard Storage Optimized S5se instances. Other types of cloud servers do not support ulTra SSD.
Enhanced SSD and ulTra SSD cannot be used as the system disk.
Enhanced SSD and ulTra SSD cannot be encrypted.
Enhanced SSD and ulTra SSD cannot be upgraded from other disk types.
Overview
Premium Cloud Disk
Tencent Cloud Premium Cloud Disk is a hybrid storage type that employs the Cache mechanism to provide high-performance storage capabilities similar to solid-state storage while ensuring data reliability through a three-copy distributed mechanism. Premium Cloud Disk is suitable for small and medium-sized applications with high data reliability requirements and moderate performance demands, such as Web/App servers, business logic processing, and small to medium-sized website construction.
Balanced SSD
Balanced SSD is an entry-level all-flash block storage product provided by Tencent Cloud. It's highly cost-effective and suitable for medium applications with high requirements for data reliability and standard requirements for performance, such as Web/App servers, business logical processing, KV services, as well as basic database services.
SSD Cloud Disk
SSD Cloud Disk is an all-flash storage type provided by Tencent Cloud based on NVMe SSD storage media. It uses a three-copy distributed mechanism, offering low-latency, high random IOPS, and high-throughput I/O capabilities, with data security up to 99.9999999%. SSD Cloud Disk is suitable for scenarios with high I/O performance requirements.
Enhanced SSD
Enhanced SSD is designed by Tencent Cloud based on the latest generation storage engine, utilizing full NVMe SSD storage media and the most recent network infrastructure. It employs a 3-copy distributed mechanism, providing low-latency, high random IOPS, high-throughput I/O capabilities, and up to 99.9999999% data security. Enhanced SSD is suitable for I/O-intensive scenarios with high latency requirements, such as large databases and NoSQL. Uniquely, Enhanced SSD supports separate configuration of performance and capacity, allowing you to tailor storage capacity and performance according to your business needs.
ulTra SSD
ulTra SSD is a high-performance distributed storage engine developed by Tencent Cloud, combined with high-speed network infrastructure and the latest generation of storage hardware, providing long-term stable and ultra-low latency reliable performance. It is ideal for I/O-intensive and throughput-intensive workloads requiring extremely low latency, such as large MySQL, HBase, and Cassandra databases, etcd and rocksdb key-value storage, Elasticsearch log retrieval, video processing, and real-time high-bandwidth live streaming. It excels in critical transaction workloads, core database operations, large OLTP tasks, and video processing scenarios. ulTra SSD uniquely supports separate configuration of performance and capacity, allowing you to customize storage capacity and performance based on your business needs.
Performance Metrics
The table below compares the performances of the five CBS services.
Performance Metrics | ulTra SSD | Enhanced SSD | SSD cloud disk | Balanced SSD | Premium Cloud Disk |
Max size (GB) | 32000 | 32000 | 32000 | 32000 | 32000 |
Max IOPS of a single disk | Up to 1,000,000 after stacking extra performance | Up to 100000 after stacking extra performance | 26000 | 10000 | 6000 |
Random IOPS Performance Calculation Formula | Basic Performance: Random IOPS = Min {4000 + Capacity (GiB) x 100, 50000} Additional Performance: Max IOPS = min{Additional Performance Value × 128, 950000} | Basic Performance: Random IOPS = Min {1800 + Capacity (GiB) x 50, 50000} Additional Performance: Maximum IOPS = Min {Additional Performance Value x 128, 50000} | Random IOPS = Min {1800 + Capacity (GiB) x 30, 26000} | Random IOPS = Min {1800 + Capacity (GiB) x 15,10000} | Random IOPS = Min {1800 + Capacity (GiB) x 8, 6000} |
Max throughput (MB/s) | Up to 4000MB/s with extra performance | Up to 1,000 MB/s with extra performance | 260MB/s | 190MB/s | 150MB/s |
Throughput performance (MB/s) | Baseline Performance: Throughput = Min {120 + Capacity (GiB) x 0.5, 350} Additional Performance: Throughput = Min {Additional Performance Value x 1, 3650} | Baseline Performance: Throughput = Min {120 + Capacity (GiB) x 0.5, 350} Additional Performance: Throughput = Min {Additional Performance Value x 1, 650} | Throughput = Min {120 + Capacity (GiB) x 0.2, 260} | Throughput = Min {100 + Capacity (GiB) x 0.2, 190} | Throughput = Min {100 + Capacity (GiB) x 0.15, 150} |
One-Way Random Read/Write Latency | 0.1ms - 0.5ms | 0.2ms - 1ms | 0.5ms - 3ms | 0.5ms - 3ms | 0.8ms - 5ms |
Note | ulTra SSD can only be purchased together with Standard Storage Optimized S5se instances. It cannot be used with other types of cloud servers, nor can it be purchased separately. | The performance of Enhanced SSD is only guaranteed when it's attached to S5, M5, and SA2 models and all later generation models. The maximum IOPS and throughput performance of Enhanced SSD is limited by the instance type it is attached to. Currently, only the latest generation S6 and SA3 instances can achieve the maximum performance per disk. The maximum storage performance metrics for different instance types will be continuously updated, so please stay tuned. | - | - | - |
Note
The main difference among cloud disks is the I/O performance.
For performance metrics, the maximum IOPS can be tested with a 4KiB IO size, and the maximum throughput can be tested with a 256KiB IO size. For specific testing methods, please refer to Measuring performance of cloud disks.
Scenarios
Enhanced SSD is more suitable for latency-sensitive or I/O-intensive scenarios, such as:
High performance and high data reliability: Suitable for high-load, mission-critical business systems. It offers triple data redundancy and comprehensive data backup, snapshot, and near-instant data recovery capabilities.
Mid and large-sized databases: support mid and large-sized relational database applications that contain tables with millions of rows, such as MySQL, Oracle, SQL Server, and MongoDB.
Large-sized NoSQL: satisfy storage performance requirements of NoSQL businesses such as HBase and Cassandra.
Elasticsearch: Support low-latency ES storage.
Video service: Suitable for applications with high requirements for storage bandwidth, such as audio/video encoding and decoding, live streaming and recording playback.
Big data analysis: suitable for data analysis, data mining, business intelligence, and other fields. Provide distributed processing capabilities for data at TB and PB levels.
ulTra SSD is suitable for latency-sensitive scenarios with extreme latency requirements, such as:
Key-Value Storage: Such as RocksDB, container etcd, etc., key-value storage often writes to disk in a serial I/O mode, with very strict requirements for the speed and latency of each I/O operation. The overall performance of the system is determined by the latency of a single path. ulTra SSD provides latency as low as tens of microseconds, making it highly suitable for core business systems that require data reliability and availability.
Large databases: Support medium and large relational database applications that contain tables with millions of rows, such as MySQL, Oracle, SQL Server, and MongoDB.
Large-sized NoSQL: satisfy storage performance requirements of NoSQL businesses such as HBase and Cassandra.
Elasticsearch: Support low-latency ES storage.
Video service: Suitable for applications with high requirements for storage bandwidth, such as audio/video encoding and decoding, live streaming and recording playback.
Core business systems: suitable for I/O-intensive applications and other core business systems with high requirements for data reliability.
Big data analysis: suitable for data analysis, data mining, business intelligence, and other fields. Provide distributed processing capabilities for data at TB and PB levels.
High performance and high data reliability: Suitable for high-load, mission-critical business systems. It offers triple data redundancy and comprehensive data backup, snapshot, and near-instant data recovery capabilities.
SSD cloud disks are more suitable for medium to large workloads, such as:
Medium databases: Medium and large relational database applications, such as MySQL.
Image processing: Support data analysis and storage businesses, such as image processing.
Common use cases for Balanced SSD Cloud Disks include:
Suitable for medium-sized applications with high data reliability requirements and moderate performance demands, such as Web/App servers, business logic processing, KV services, and basic database services.
Primary use cases for premium cloud disks include the following data scenarios:
Small and medium databases and Web/App servers. Provide long-term and stable I/O performance.
Scenarios that require balanced storage capacity and performance, such as enterprise office services.
Satisfy I/O requirements for core business testing and developing joint testing environments.