We introduced Amazon S3 in March of 2006. S3 growth over the past 6+ years has been strong and steady, and it now stores over one trillion objects. Glacier builds on S3's reputation for durability and dependability with a new access model that was designed to be able to allow us to offer archival storage to you at an extremely low cost.
To store data in Glacier, you start by creating a named vault. You can have up to 1000 vaults per region in your AWS account. Once you have created the vault, you simply upload your data (an archive in Glacier terminology). Each archive can contain up to 40 Terabytes of data and you can use multipart uploading or AWS Import/Export to optimize the upload process. Glacier will encrypt your data using AES-256 and will store it durably in an immutable form. Glacier will acknowledge your storage request as soon as your data has been stored in multiple facilities. Creating a vault in Amazon Glacier.
Glacier will store your data with high durability (the service is designed to provide average annual durability of 99.999999999% per archive). Behind the scenes, Glacier performs systematic data integrity checks and heals itself as necessary with no intervention on your part. There's plenty of redundancy and Glacier can sustain the concurrent loss of data in two facilities.
At this point you may be thinking that this sounds just like Amazon S3, but Amazon Glacier differs from S3 in two crucial ways.
First, S3 is optimized for rapid retrieval (generally tens to hundreds of milliseconds per request). Glacier is not (we didn't call it Glacier for nothing). With Glacier, your retrieval requests are queued up and honored at a somewhat leisurely pace. Your archive will be available for downloading in 3 to 5 hours.
Each retrieval request that you make to Glacier is a called a job. You can poll Glacier to see if your data is available, or you can ask it to send a notification to the Amazon SNS topic of your choice when the data is available. You can then access the data via HTTP GET requests, including byte range requests. The data will remain available to you for 24 hours.
Retrieval requests are priced differently, too. You can retrieve up to 5% of your average monthly storage, pro-rated daily, for free each month. Beyond that, you are charged a retrieval fee starting at $0.01 per Gigabyte (see the pricing page for details). So for data that you’ll need to retrieve in greater volume more frequently, S3 may be a more cost-effective service