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, so it 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 storage class when you upload the object.

Changing the storage class of a bucket does not change the storage class of existing objects in the bucket. However, any new objects uploaded to the bucket will inherit the bucket's new storage class.

Comparison of Storage Classes

Compared Item	Standard	Warm	Cold
Feature	Top-notch performance, high reliability and availability	Reliable, inexpensive storage with real-time access	Long-term, inexpensive storage for Cold data
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 unit^a NOTE: 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 duration^b NOTE: 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.	N/A	30 days	90 days
Data restore	N/A	Billed for each GB restored.	Data can be restored at an expedited or a standard or bulk speed. Billed for each GB restored.

Storage Classes Overview

Bucket Storage Classes vs. Object Storage Classes

Comparison of Storage Classes