Storage Classes Overview

OBS supports tiered storage classes at the bucket level and object level.

OBS provides the following storage classes: Standard, Warm, and Cold.

These storage classes can meet different needs for storage performance and costs.

  • Standard: The Standard storage class features low latency and high throughput. It is therefore good for storing frequently (multiple times per month) accessed files or small files (less than 1 MB). Its application scenarios include big data analytics, mobile apps, hot videos, and social apps.

  • Warm: The Warm storage class is for storing data that is infrequently (less than 12 times per year) accessed, but when needed, the access has to be fast. It can be used for file synchronization, file sharing, enterprise backups, and many other scenarios.

  • Cold: The Cold storage class is ideal for storing data that is rarely (once per year) accessed. Its application scenarios include data archive and long-term backups. The Cold storage class is secure, durable, and inexpensive, and can be used to replace tape libraries. To keep cost low, it may take hours to restore data from the Cold storage class.

Bucket Storage Classes vs. Object Storage Classes

When an object is uploaded, it inherits the storage class of the bucket by default, but you can change the default storage class when you upload the object.

Changing the storage class of a bucket does not change the storage classes of existing objects in the bucket, but newly uploaded objects will inherit the new storage class.

Comparison of Storage Classes

Compared Item





Top-notch performance, high reliability and availability

Reliable, inexpensive storage with real-time access

Long-term storage for Cold data at a low cost

Application scenarios

Cloud application, data sharing, content sharing, and hot data storage

Web disk applications, enterprise backup, active archiving, and data monitoring

Archive, medical image storage, video material storage, and replacement of tape libraries

Minimum measurement unita


a: Minimum measurement unit refers to a minimum billable object size. For example, a 32 KB Standard object will be billed as if it were 64 KB.

64 KB

64 KB

64 KB

Minimum storage durationb


b: Minimum storage duration refers to a minimum billable storage duration. For example, an Infrequent Access object deleted when it was stored for 20 days will be billed for a full 30 days.


30 days

90 days