What are LTO Tape Drives and are they better than NAS?
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I see LTO-8 drives sell for $3500 or so. LTO-8 tapes seem to be selling for about $120 or so today (although I couldn't find them a year ago back when a patent war was keeping them off the market)
The LTO-8 tape has 12 TB capacity. I see 12TB hard drives selling for $270. You save $150 using a tape instead of a hard drive, so you have to replace 23 disks with tapes to make back the cost of the drive, or a total of 276 GB of storage.
My experience is that you can write a sector to a hard drive and read it back correctly with p = 1-1e^-6 or so. I've never had the experience of backing up files onto an external hard drive and not being able to restore them, except in the case where somebody hit the drive with a hammer to pulverize the platters.
My experience with tapes is that "real world" failures happen at an 0.5-0.9 rate unless you're in a workflow where you restore from tape EVERY DAY. If you don't believe me, I suggest that you try it. Frequently I've seen people write a tape with my own eyes then tried to read the tape and found nothing but zeroes. One time I tried to restore a 4kb configuration file and was told by the IBM tape robot I'd have to wait 18 hours!
Tape is marketed at the "enterprise" -- which is why the prices are where they are for drives and tape cartridges.
Enterprises that have regulatory requirements for multiple "off-site" backups buy these, as they allow them to check the "complies" box on their compliance forms they file quarterly.
But as enterprise customers are also low volume compared to the mass market, both the drives and tape cartridges are priced to recoup the design/build costs across a smaller number of units sold.