Cloud Disk Service (CDS)-Baidu AI Cloud

Cloud Disk Service (CDS)

CDS is a block storage service with low latency, persistence, high reliability and elasticity. CDS data is redundantly stored in the availability zone in the form of multi-replica to avoid the single-node failure risk of the data. It supports the elastic management of CDS by the on-line scaling and change of disk type after the purchase.

Overview

CDS provides the data storage service with high availability and capacity for Baidu Cloud Compute (BCC). You can format, partition and create the file system for the block storage mounted to the BCC instance. CDS adopts the redundant multi-replica storage technology to ensure the reliability of CDS data. Furthermore, it supports the snapshot service to prevent the risk in loss of the business data, resulted from the improper deletion, BCC downtime and physical server downtime and other irresistible disasters. CDS provides five types of block storage, i.e., general-purpose SSD, high throughput HDD, high-performance CDS, general-purpose HDD and Sata CDS.

Disk Type

CDS Type	General SSD	High-performance CDS	High-throughput HDD	General HDD
Application Scenarios	It uses the high-performance SSD for the I/O intensive applications, such as the large OLTP business.	It is highly cost-effective and is applicable for most application scenarios with high IO, such as the small and medium database and core business test and development environment.	It is the low-cost HDD CDS with high throughput and applicable for most application scenarios with low IO and high throughput, such as the log storage.	It is low-price, high-throughput, and cost-effective. It is applicable for the price-sensitive scenarios with the throughput requirements.
Capacity per CDS	50 GB ~ 32 TB	5 GB ~ 32 TB	5 GB ~ 32 TB	5 GB ~ 32 TB
Maximum random IOPS per CDS	25000	5000	800	500
Upper limit of IOPS bursts per CDS	25000	5000	800	500
Maximum throughput per CDS	300 MBps	140 MBps	400 MBps	200 MBps
Performance calculation formula	IOPS=min{1800+30capacity,25000} capacity=min{120+0.5capacity,300} MBps	IOPS=min{1800+8capacity,5000} capacity=min{100+0.15capacity,140} MBps	IOPS=min{200+1capacity,800} capacity=min{30+0.039capacity,400} MBps	IOPS=min{200+1capacity,500} capacity=min{30+0.012capacity,200} MBps
Access latency	Less than 2ms	Less than 3ms	Less than 10ms	Less than 10ms
Data Reliability	99.9999999%	99.9999999%	99.9999999%	99.9999999%
Price	0.90CNY/GB/month	0.35CNY/GB/month	0.35CNY/GB/month	0.30CNY/GB/month
Remarks	The performance of general-purpose SSD, high-performance CDS, high throughput HDD, and general-purpose HDD linearly increases with the capacity. For example, when you purchase 100 GB HDD with high IO, its peak performance is random IO 2,600 IOPS, and the throughput is 115 MBps.

Features

Multiple CDS types

Reliable Data Storage

On-line Scaling and Type Switching

Quick Business Deployment

Diverse Management

Flexible Billing Mode

General SSD

The general-purpose SSD balances the performance and price, and provides high IO and throughput. It is applicable for the I/O intensive applications, and can be used as the key workload of most core businesses, such as the large OLTP business and enterprise core business system.

High-performance CDS

It has high IO and is cost-effective. It is applicable for most application scenarios with high IO requirements, such as the small and medium database, core business test and development environment.

High-throughput HDD

It is the low-cost HDD CDS with high throughput. It is applicable for most application scenarios with low IO and high throughput, such as the service log storage and data warehouse.

General HDD

It is in low price and applicable for HDD CDS in general business scenarios. It is applicable for the general business scenarios with low IO and certain throughput requirement and the cost-sensitive scenarios.

Sata CDS

It is in low price and applicable for the business scenarios with infrequent access, such as the test scenario and personal business scenario.

Advantages

High Performance

The storage node of general-purpose SSD and the BCC host use the 10 Gigabit network and the SSD medium, which do not only meet the requirements for high read/write throughput and high IOPS, but also ensure the stability of read/write delay.

Reliable and Stable

The distributed redundant multi-replica storage technology and the snapshot backup feature ensure the availability and reliability of your data.

Performance Burst

It provides the exclusive performance burst ability in China, and the IO performance can be burst to the maximum performance of the same type, in stable response to the IO pressure brought by the business peak.

Multiple Product Forms

SSD, various HDDs, and Sata CDS can meet your business requirements. After the purchase, you can on-line switch the CDS types  to adapt to the business change.