Too many people on here saying "disk is better than tape" are thinking too small. If you have say 50TB of data, and you need to keep daily copies for a few months, monthly copies for a few years, and yearly copies for 27 years, how do you propose to store all THAT on disk?

Disk cannot be taken offsite, unless you put the disk offsite. However an offsite disk array can blow away all your data in a single shot if it dies/somebody does something bad etc. Whereas it would take thousands of mistakes to wipe thousands of tapes.

For those who are concerned about reliability - that's why these ENTERPRISE drives are so expensive - they are damn reliable. I use older 3592 type drives (an older relation to the one in this article) and they are exceptionally reliable, maybe 1 or 2 tape errors per year, and 1 drive error every 2-3 years, thats with 10 drives and writing about 5TB of data per night, and doing about 100-150 tape mounts every 24 hour period.

And tapes don't use electricity or need cooling when they're not in use.

So stop thinking about your own small environment and consider those with bigger requirements than yours, protecting data which really is critical (lives depend on it etc).