Let’s start the the high level. Amazon Simple Storage Service, better known as S3, offers a super durable, scalable storage solution. It offers 99.999999999% durability, also known as eleven 9’s. This means that once every 10,000 years you would lose some data in S3. All S3 tiers offer encryption at rest and the ability to move data to different storage classes using lifecycle policies. There are seven flavors of S3. Standard, Standard-Infrequently Accessed, Intelligent Tiering, One Zone-Infrequently Accessed, Glacier and Glacier Deep Archive.
This is your most expensive S3 option. The key thing to remember about S3 standard is that it is for frequently accessed data. It has a 99.99% availability. IT also provides protection from destruction of an availability zone, and has eleven 9’s of durability. This high availability and durability comes with the steepest price tag at $0.023 per GB.
Standard — Infrequently Accessed
Infrequently accessed or IA describes itself. It’s intention is for long term storage of infrequently accessed data. IA offers eleven 9’s of durability and 99.9% availability. IA, like standard, offers protection against the destruction of an availability zone. Due to the intent for IA data to be long lived there is a minimum charge time of 30 days and you are charged $0.01 per GB of data retrieval. IA has a cost of $0.0125 per GB of data stored.
Intelligent tiering is a new offer from AWS, having its introduction back in 2018. The promise of intelligent tiering is that it will put data in either standard or IA depending on access patterns. It offers eleven 9’s of durability and 99.9% availability. The cost is the same as standard or IA depending on where your data location. There is a monitoring fee of $0.0025 per 1,000 objects charged by AWS for using this tier.
One Zone — Infrequently Accessed
One zone IA is like IA except your data is only kept in one availability zone. This carries more risk, as you no longer have a redundancy of your data. For the increased risk you get a cheaper price of storage though at $0.01 per GB. The availability here is lower at 99% but the durability is, as always, eleven 9's.
Glacier is where the S3 tiers start to differ in purpose. Glacier and Glacier Deep Archive are for long term storage of data that you may never need to access. In return for being patient you get the cheapest cost of storage. The long retrieval times are the limiting factors that will drive the decision to use these tiers.
Glacier storage costs are $0.004 per GB. There are three options you can choose between when retrieving data from Glacier. First is expedited, data retieved with expedited is usually available in 1–5 minutes. Expedited will cost $0.03 per GB and $0.01 per request. Second is standard, a standard retrieval will return you data in 3–5 hours. Standard retrievals will cost you $0.01 per GB and $0.05 per 1,000 requests. Last is bulk, this retrieval takes around 5–12 hours. Bulk retrievals will cost you $0.0025 per GB and $0.025 per 1,000 requests. Glacier also charges for a minimum of 90 days of storage.
Glacier Deep Archive
Deep Archive offers storage costs of $0.00099 per GB or about $1 per TB. While this is ridiculously cheap it has a very specific use case of ultra long tem storage often required for highly regulated industrys. The idea here is that you would only be accessing this data once or twice a year at most. There is no expedited retrieval option here, only standard and bulk. Standard will return your data in 12 hours and bulk 48 hours. It has the usual eleven 9’s of durability and 99.99% availability. There is a minimum storage time of 180 days.