There are lots of different thoughts. I'm not convinced that there's a single silver bullet that's the best all-around medium for all types of archiving or environments. But, there are some very good mediums, including disk drives, which are both fixed and removable. Some drives can even "sleep" where they spin down for prolonged periods to save power and wear on the drive mechanism. Another option for archive besides traditional tape...
solutions, in which the tape cartridges do not consume power when not in use, are removable disk drives that can be placed into existing robotic tape libraries providing a hybrid benefit of random access of disk, with the power saving benefits of traditional tape. Removable disk drives can be sent off site like tape cartridges. Even traditional tape is still employed for archiving. Optical WORM drives are also used, though these occupy more of a storage niche.
The choice of medium for file archiving really depends on your preferences and business needs, so there are many options to choose from, each with varying levels of capacity, performance, data preservation capability, reliability and cost effectiveness (not necessarily the cheapest). Consider your requirements, including the features that you absolutely must have, and then contemplate any value-added features, such as compression, data deduplication or replication.
Go back to the beginning of the File Archiving FAQ Guide.