[Darryl Ramm]

Tape had its day but it is dead. And more IT departments might be in for a surprise if they actually went and tried to read lots of old archive tapes.

It all depends on what timeframe of archiving you look at, but more and more modern large scale enterprise IT and web scale archives are magnetic disk based. With disks spun down or even powered down to save power.

At all cost avoid proprietary formats, they can be harder to fix if the media/system has problems and the company goes out of business. Do not rely on a single archive. Spread the risk around with a combination of backup/archiving to magnetic disk, optical disk (e.g. DVD-ROM) and cloud based backup. Have an indexing/labeling system where you have a hope of finding something. Whoever develops that needs to document it for others. Written down rules for staff to follow. And get some of those optical or external disk archives off-site in a media storage facility or safety deposit box (use several different sites). Be sure to keep a system around that can read your archives, it may need to be a system with say SATA III drives, and a DVD-ROM drive well past both those technologies being popular. And if this stuff has any significant value you need to try reading it every so often. If archives are failing, duplicate those from other media.