Categories: AWS

Amazon S3 Storage Classes Explained

For different usage scenarios, Amazon Web Services offers different storage classes. This allows reducing the storage costs for data which is rarely used, and doesn’t require instant access. All the classes have a high level of reliability and support SSL data encryption during transmission, but differ by their cost

This article will outline where and which class is recommended for use, and what the difference between Amazon S3 storage classes is.

Table of Contents

    Amazon S3 Standard

    Amazon S3 Standard is designed for high-usage, “hot” data storage and has the following features:

    • High capacity and low latency.
    • Reliability at 99,999999999% level (of 100 billion objects per year, you are at risk of losing only one of them).
    • Availability at 99,99% level (of 10 thousand hours, within one hour the data will be unavailable).
    • Use of the storage is covered by Amazon S3 Service Level Agreement, which considers a compensation if the level of uninterrupted operation is lower than it was declared.

    Standard storage is suitable for the following usage scenarios:

    • Website hosting.
    • Cloud applications and web-services.
    • Mobile games and apps.
    • Big data.
    • Content distribution.

    Amazon S3 RRS

    Amazon S3 Reduced Redundancy Storage (RRS) allows to reduce the storage costs for replicable, uncritical data. This can be achieved through reduction of redundancy and decreasing a replicas number. The main difference between RRS and S3 Standard is reliability at 99,99%. It means that, on average, if you store 10,000 objects, within a year, you are at risk of losing only one of them.

    This solution is perfect for uncritical or easily replicable data of different apps: dynamic websites, business-applications, etc. For example, you can use Amazon S3 Standard for keeping images, and S3 RRS — for their previews.

    Amazon S3 Standard Infrequent Access

    Amazon S3 IA is designed for the data which require less frequent access, but with longer storage time than in case of Standard.

    Low delays combined with high capacity and reliability 99,999999999% insure the safety of object for a long period of time. Amazon S3 IA differs from Standard in the following way:

    • Availability at 99.9% level within a year (e.g., the probability of request error is a little higher than in standard storage).
    • You are charged for data retrieval.

    Minimum storage period is 30 days, and the minimum size of the object is 128 KB. The storage is recommended for long storage of files, disaster recovery data, backup, outdated sync data. As a rule, they require access relatively rarely, but, if necessary must be accessed quickly. In CloudBerry Backup, you can use S3 Standard IA class as a standard destination for your backups.

    Amazon S3 One Zone - Infrequent Access

    In April 2018, Amazon Web Services has introduced yet another Amazon S3 storage class - Amazon S3 One-Zone Infrequent Access. It is 20% less expensive than Amazon S3 Standard IA due to lesser availability - 99.5% level within a year. It's naming is really all there is to say about that class - instead of three availability zones, Amazon S3 Z-IA stores data in only one.

    Amazon Glacier

    Amazon Glacier is a perfect solution for long storage and archiving of data which don’t require instant access. The service allows storing large or small volumes of data at low cost. At the same time, the retrieval process may take several hours. Amazon Glacier differs from S3 Standard in the following way:

    • Extremely low cost.
    • Uninterrupted operation is not guaranteed by Amazon S3 Service Level Agreement.
    • The minimum period of storage is 90 days.

    There is a charge for data retrieval of more than 10 GB free tier per month. Access to data is limited depending on the chosen retrieval options (expedite retrieval - 1-5 minutes, standard - 3-5 hours, bulk - 5-12 hours) The service is optimized for the data, for which the access is rarely required, with admissible retrieval time of several hours.

    The typical example of use is the storage of data archives:

    • Media resources archives (news bulletins).
    • Archives of organizations working in the health area (patients information).
    • Data obtained during scientific researches.
    • Backup copies of databases with long storage.
    • Replacement of analog media.

    You can save objects directly in Glacier or set a Lifecycle Policy on your S3 bucket to automatically archive data.

    Lifecycle Policy

    All Amazon S3 classes are supported by lifecycle policy. It means that you can optimize the storage costs for the objects by setting the rules of their automatic transference to cheaper storage. It is also possible to set up the life cycle termination policy so that the files were automatically removed after a certain period.

    For example, you can save your data in Amazon S3 Standard, in a certain time transfer it to Standard IA storage, and then - to Glacier. Sometime later it can be removed or placed to archive storage.


    CloudBerry Backup supports all Amazon S3 storage classes and features, including S3 Standard IA. We suggest you evaluate CloudBerry Backup Ultimate Edition during a 15-day free trial period, so you could benefit from combined features of Amazon S3 and CloudBerry Backup.

    We also prepared a small comparison of storage class features for AWS:

    S3 Standard S3 RRS S3 Standard IA S3 Z-IA Glacier
    Redundancy 99,999999999 % 99,99 % 99,999999999 % 99,999999999 % 99,999999999 %
    Availability 99,99 % 99,99 % 99,9 % 99,5 N/A
    The minimum period of storage Unlimited Unlimited 30 days 30 days 90 days
    The minimum size of the object Unlimited Unlimited 128KB (for less you are charged as for 128KB) 128KB (for less you are charged as for 128KB) Unlimited
    Access to the object Milliseconds Milliseconds Milliseconds Milliseconds 1 minute - 12 hours, depending on the retrieval options
    Charge for data retrieval None None Per GB of the data retrieved Per GB of the data retrieved 10 GB per month free, then per GB of the data retrieved

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