Big data isn’t just about Hadoop distributions and analytics software — you also need servers to process it and disks on which to store it. On Tuesday, research firm IDC quantified the market for the latter aspect, predicting that the business of selling storage into big data deployments will be worth nearly $6 billion in 2016, up from just $379.9 million in 2011.

However, as a press release explaining the new report highlighted, defining “storage” for the purposes of big data is an exercise in subjectivity. There are systems for archiving data, and systems for storing post-processed data and systems — like the Hadoop Distributed File System — that put storage on the same servers that process data. There also are storage systems designed for operational data and those designed for transactional data, and very likely something in between.

Presumably, these numbers don’t account for the amount of storage baked…