Alibaba Cloud provides a wide variety of block-level storage products for ECS. These include elastic block storage based on the distributed storage architecture and local disks located on the physical servers where ECS instances are hosted. Specifically:
Elastic block storage, is a low-latency, persistent, and high-reliability random block-level data storage service provided by Alibaba Cloud to ECS users. It uses a triplicate distributed system to provide 99.9999999% data reliability for ECS instances. Elastic block storage can be created, released, and resized at any time.
Local disks are the disks attached to the physical servers (host machines) that ECS instances are hosted on. They provide temporary block-level storage for instances, featuring low latency, high random IOPS, and high I/O throughput. They are designed for business scenarios requiring high storage I/O performance.
For more information about the performance of block-level storage products, see Storage parameters and performance test.
Block storage, OSS, vs. NAS
The differences are as follows:
Block storage: A high-performance and low-latency block-level storage device provided by Alibaba Cloud to ECS users. It supports random reads and writes. You can format the block storage and create a file system on it as you would with a hard disk. Block storage can be used for data storage in most common business scenarios.
OSS: A huge storage space, which is suitable for storing massive unstructured data, including images, short videos, and audio files generated on the Internet. You can access the data stored in OSS anytime and anywhere by using APIs. Generally, OSS is used for business scenarios as Internet business website construction, separation of dynamic and static resources, and CDN acceleration.
NAS: A storage space for massive unstructured data, like OSS. For NAS, you must access the data by using standard file access protocols, such as the Network File System (NFS) protocol for the Linux system, and the Common Internet File System (CIFS) protocol for the Windows system. You can set permissions to allow different clients to access the same file at the same time. NAS is applicable to business scenarios such as file sharing across departments, radio and television non-linear editing, high-performance computing, and Docker.