> Whereas they are generally more reliable than an hard drive, for the same investment you can just buy more drives and make up for it,
I would love to see how you make this miracle happen, because it would make my life easier.
My numbers currently favor tape heavily. LTO-6 media is less than $25/TB, whereas spinny disks are $40/TB, and if those hard drives are going to be plugged in, add a minimum $10/TB for connecting them to something.
LTO-4/5/6 media was always pricier for me whenever I was using it.
But most importantly, a tape robot costs orders of magnitude more. And if you don't have one, you either need multiple drives or fit the whole archive into one tape.
Now, if at home you can easily reach 2TB per-disk and have ~10TB easily, a nas with 8-16 disks in any work place will easily be too large for a single tape to be useful. A tape robot will be out of reach (in economical and logistical terms).
In these conditions, you really need a _huge_ system to make tape economically viable, but that's a very small market, whereas buying harddrives and cycling them will be the only logical choice.
Tape used to be different, where you could fit a week of incremental backups into one in the eighties. That made tape worthwhile. Then HD became more dense, while tape struggled.
I'm thinking of backing up on the order of 100TB a month, in which case a tape robot starts to make sense financially, but is a pain when it comes to software.
We're currently "backupping" ~300TB, and we chose delayed replication on a secondary site after evaluating several solutions.
With hashbackup (http://www.hashbackup.com/ - not related in any way, just a happy user), we can squeeze roughly one year of history using a differential daily/weekly/monthly schedule.
It's faster than tape, and much easier to manage. If you account for electricity though, it's not much cheaper. But as we scale our storage, we can scale the other site as well (replacing hdds with higher capacity), which has allowed us to move from ~100TB to the current size without any change.
That being said, if I had a high density tape (as advertised), I would definitely choose tape. I don't think I need to explain the benefits of having multiple copies.
I would love to see how you make this miracle happen, because it would make my life easier.
My numbers currently favor tape heavily. LTO-6 media is less than $25/TB, whereas spinny disks are $40/TB, and if those hard drives are going to be plugged in, add a minimum $10/TB for connecting them to something.