Alibaba Cloud Object Storage Service (OSS) supports all types of data, including images, audio files, video files, documents, software packages, files in CSV, JSON, and Parquet formats, and backup files. Every object stored in a bucket has a storage class that determines how the data is stored, how quickly it can be retrieved, and how much it costs.
By default, objects stored in OSS use the Standard storage class. OSS also offers Infrequent Access (IA), Archive, Cold Archive, and Deep Cold Archive storage classes for data with different access patterns.
How to choose a storage class
When selecting a storage class, evaluate the following factors:
| Factor | Description | Range |
|---|---|---|
| Access frequency | How often you read and write data | Frequent to rare |
| Retrieval time | How quickly you need to access the data | Real-time to hours or days |
| Availability | The probability that OSS is operational within a given period | 99.00% to 99.995% |
| Durability | The security and integrity of data stored in OSS within a given period | 99.999999999% (eleven 9's) to 99.9999999999% (twelve 9's) |
Redundancy types
Each storage class can be combined with a redundancy type that controls how your data is distributed across storage infrastructure:
| Redundancy type | Distribution | Durability | Supported storage classes |
|---|---|---|---|
| Zone-redundant storage (ZRS) | Across multiple availability zones | 99.9999999999% (twelve 9's) | Standard, IA, Archive |
| Locally redundant storage (LRS) | Within a single availability zone | 99.999999999% (eleven 9's) | Standard, IA, Archive, Cold Archive, Deep Cold Archive |
Storage class specifications
The following table lists the access frequency, retrieval time, availability, and durability for each combination of storage class and redundancy type.
| Storage class | Access frequency | Retrieval time | Availability | Durability |
|---|---|---|---|---|
| Standard zone-redundant storage (ZRS) | Frequently accessed | Real-time access | 99.995% | 99.9999999999% (twelve 9's) |
| Standard locally redundant storage (LRS) | Frequently accessed | Real-time access | 99.99% | 99.999999999% (eleven 9's) |
| IA ZRS | Infrequently accessed | Real-time access | 99.50% | 99.9999999999% (twelve 9's) |
| IA LRS | Infrequently accessed | Real-time access | 99.00% | 99.999999999% (eleven 9's) |
| Archive ZRS | Seldom accessed | Real-time access or 1 minute | 99.50% | 99.9999999999% (twelve 9's) |
| Archive LRS | Seldom accessed | Real-time access or 1 minute | 99.00% | 99.999999999% (eleven 9's) |
| Cold Archive LRS | Rarely accessed | 1 to 12 hours | 99.00% | 99.999999999% (eleven 9's) |
| Deep Cold Archive LRS | Rarely accessed | 12 or 48 hours | 99.00% | 99.999999999% (eleven 9's) |
The following table summarizes the typical use cases for each storage class.
| Storage class | Access pattern | Typical use cases |
|---|---|---|
| Standard | Frequently accessed, real-time retrieval | Active application data, content delivery, big data analytics |
| Infrequent Access (IA) | Infrequently accessed, real-time retrieval | Data accessed once or twice a month, backups with occasional retrieval |
| Archive | Seldom accessed, retrieval in real-time or 1 minute | Long-term archival data that may need occasional access |
| Cold Archive | Rarely accessed, retrieval in 1 to 12 hours | Compliance archives, long-term backups |
| Deep Cold Archive | Rarely accessed, retrieval in 12 or 48 hours | Data retained for regulatory or historical purposes with minimal retrieval needs |
For more information about the pricing for each storage class, visit the OSS pricing page.