Amazon Glacier is an extremely low-cost storage service that offers durable, secure and flexible storage for online data archiving and backup.
To reduce costs, Amazon Glacier is designed for data accessed infrequently, where a three to five hour recovery time is acceptable.
Amazon Glacier can store an unlimited amount of virtually any type of data, in any format.
Common use cases for Amazon Glacier include replacing traditional tape solutions for long-term backup and archiving and storage of data required for compliance purposes. In most cases, the data stored in Amazon Glacier consists of large TAR (Tape Archive) or ZIP files.
Like the Amazon S3, the Amazon Glacier is extremely durable, storing data on multiple devices in multiple installations in one region. Amazon Glacier is designed for 99.99999999999% of object durability over a given year.
In Amazon Glacier, data is stored in files. A file can contain up to 40TB of data and you can have an unlimited number of files. Each file receives a unique file ID at creation time. (Unlike an Amazon S3 object key, you can not specify a file-friendly name.)
All files are encrypted automatically and files are immutable – after creating a file, it can not be modified.
Vaults are containers for files. Each AWS account can have up to 1,000 vaults. You can control access to your vaults and the actions allowed using IAM policies or vault access policies.
You can easily implement and enforce compliance controls for individual vaults as a vault blocking policy. You can specify controls such as Write Once Read Many (WORM) in a vault block policy and block the policy from future issues. Once locked, the policy can no longer be changed.
You can recover up to 5% of your data stored in Glacier for free, monthly, calculated daily.
If you recover more than 5%, you will have recovery fees based on your maximum recovery rate. To eliminate or minimize these fees, you can define a
data recovery policy in a safe to limit your recoveries to the free or at a specific data rate.
Amazon Glacier x Amazon Simple Storage Service (Amazon S3)
Amazon Glacier is similar to Amazon S3, but differs in several important ways. Amazon Glacier supports 40 TB files versus 5 TB objects on Amazon S3.
Files in Amazon Glacier are identified by system-generated file IDs, while Amazon S3 allows you to use “friendly” key names.
Amazon Glacier files are automatically encrypted, while resting encryption is optional on Amazon S3. However, using Amazon Glacier as an Amazon S3 storage class along with object lifecycle policies, you can use the Amazon S3 interface to get most of the benefits of Amazon Glacier without learning a new interface.