Amazon Glacier vs Amazon S3: What are the differences?

Introduction

In this article, we will discuss the key differences between Amazon Glacier and Amazon S3, two popular cloud storage services offered by Amazon.

1. Storage Architecture: Amazon Glacier is designed for long-term data archival and backup while Amazon S3 is primarily used for frequently accessed data storage. Glacier offers a slower retrieval time (usually hours) and lower storage costs compared to S3, making it suitable for data that doesn't require immediate retrieval. On the other hand, S3 provides faster retrieval times and is ideal for storing more frequently accessed data.

2. Data Accessibility: In Glacier, retrieving data can be a time-consuming process with retrieval times ranging from several minutes to hours. This delay is due to the storage architecture and the need for data to be restored from the archives. In contrast, Amazon S3 offers immediate access to stored data, with virtually no retrieval delay. This difference in accessibility is crucial for applications that require fast data access and real-time processing.

3. Storage Costs: Glacier offers significantly lower storage costs compared to Amazon S3. Glacier's pricing model is based on the amount of data stored and the retrieval time required. It is most cost-effective for data that is rarely accessed. In contrast, Amazon S3 has higher storage costs but is more suitable for frequently accessed data where retrieval time is crucial.

4. Data Durability: Both Glacier and S3 ensure high data durability. However, Glacier provides an additional layer of durability by automatically creating multiple copies of data within multiple availability zones. This extra protection adds an extra layer of redundancy, making Glacier a more reliable choice for long-term data storage and archival purposes.

5. Data Lifecycles: Amazon S3 supports lifecycle policies that allow for automated transitions of data between different storage classes. This feature enables the movement of data from S3 to Glacier for cost savings once the data becomes less frequently accessed. On the other hand, Glacier does not support lifecycle policies and is designed specifically for long-term archival, without the need for frequent transitions or retrieval.

6. Access Control and Permissions: Both Glacier and S3 offer fine-grained access control and permission management. However, S3 provides more flexibility in terms of access control, allowing granular control at both the bucket and object level. It supports complex access control policies and integrates with other AWS services for more extensive permission management. Glacier, while still maintaining access control capabilities, has a simpler permission model compared to S3.

In summary, the key differences between Amazon Glacier and Amazon S3 lie in their storage architecture, data accessibility, storage costs, data durability, data lifecycles, and access control and permissions. Glacier is best suited for long-term data archival and backup with low storage costs but slower retrieval times. S3 is ideal for frequently accessed data with faster retrieval times, higher storage costs, and more advanced access control capabilities.