Amazon Web Services – Simple Storage Service (aka “AWS S3″, or just “S3″) is was onle of the first pay-as-you-go self-serve cloud storage services made available, and is still one of the most popular. If you have never heard of S3 before, then you have lots to learn, my friend!
S3 really is quite simple. You first need to sign up for an AWS account (this requires a credit card, of course). Once you have yo AWS account, you then create one of more buckets in the S3 system. You can think of a bucket similar to a hard-drive. Inside a bucket, you can then create folders and files, just like on a hard drive. Since S3 is a metered service you pay only for what you use (the transfer is priced separately from the storage itself). Prices (per GB) become cheaper as you use more (volume discounting), and there is also a free tier that gives you a certain amount of usage for free, so you can experiment quite a bit and not even be charged a penny for it.
You can access S3 from the AWS web console using your web browser, or from various command line tools (e.g. s3cmd) or you can use their web-services API to access S3 from your own software. There are libraries for most of the popular languages (Ruby, Python, etc.) which makes it quite painless to get started.
S3 offer a few advanced features that make it especially useful:
- File checksums are generated automatically, and you can access these via the API.
- Flexible access controls allow you to share files with other users, or make them public.
- Files can be automatically migrated to AWS Glacier for archival storage, which is even cheaper. Just keep in mind that when files have been moved to Glacier they are not immediately accessible, instead they must be thawed (moved back to S3) and that process takes several hours.
Pricing for S3 is somewhat unintuitive, because you pay for the actual transfer AND for monthly storage. Data transfers between S3 and EC2 instances are free, so you get that benefit if you also use EC2 as your compute service. For pricing details, see the AWS S3 pricing page.
If you are currently using S3, or have used it recently, please comment on what you like/dislike about it. This will let other readers know what to expect, and help them select the best service for their needs. Thanks!