Amazon Glacier: archiving on demand at low prices

Amazon has announced a new product in its Amazon Web Services cloud suite. Amazon Glacier is designed for archiving. According to the service description, you get redundant storage over “multiple facilities and on multiple devices within each facility” with regular data integrity checks, giving annual durability which Amazon works out somehow as 99.999999999%.

Storage pricing is $0.011 per GB / month. So keeping a cloud-based copy of that 1TB drive you just bought is $11.00 per month or $132 per year. Not a bad price considering the redundancy and off-site problem that it solves, as long as you can live with sub-contracting the task.

For comparison, Amazon S3, which is designed for day to day storage, costs  $0.125 per GB for the first 1TB, falling to $0.055 per GB for 5000 TB or more, or $0.037 per GB for what Amazon calls “reduced redundancy storage”. Glacier is less than one third of the price.

Note that Glacier is not suitable if you need to get at the data quickly:

You can download data directly from the service using the service’s REST API. When you make a request to retrieve data from Glacier, you initiate a retrieval job. Once the retrieval job completes, your data will be available to download for 24 hours. Retrieval jobs typically complete within 3-5 hours.

In other words, you cannot retrieve data directly. You have to ask for it to be made available first. Glacier is not a cheap alternative to S3, other than for archiving.

There are additional charges for retrieving data beyond 1GB per month, $0.12 per GB falling to $0.050 per GB for over 350 TB, or less for very large retrievals. It is well known that beyond a certain amount, it is quicker and cheaper to send data on the back of a truck than over the internet.