A few years back, Amazon introduced a somewhat bizarre sounding file backup service. Unlike an ordinary S3 bucket, Glacier was designed to protect data that you didn’t constantly need access to. As the name implies, it’s a sort of digital cold storage. It also moves slowly, like a Glacier would. If you need to retrieve some files, it can take three to five hours to “thaw” them. Ever since the service was announced, people (geeky ones, anyway) have been wondering what kind of hardware Amazon Glacier uses that lets them charge such ridiculously low rates. Storage is never cheap when you’re talking about petabytes of data, but if Amazon’s only charging 1 cent per gigabyte of geo-distributed secure storage they must be …

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Amazon uses Blu-ray disc to archive data, just like Facebook