Don't underestimate the bandwidth of a stationwagon full of tapes hurling down the highway.
As a hobby, I've looked into second-hand LTO tape backup for my 71 TB NAS but the drive alone is pricey, and if it dies, how can I restore my data without forking over too much money?
> if it dies, how can I restore my data without forking over too much money?
In the unlikely event your NAS dies at the same time as your LTO tape drive, then you buy a replacement drive, restore the tapes, and sell the drive again on eBay, recouping most of your costs.
Fun anecdote... Many years ago, we had to send a large dataset from the east coast to the west coast. I think we had a 10 or 100Mbps WAN connection (this was the 90s). It was faster to freight airship the entire storage device than send it over the wire (which we did).
The amazing thing is that, at current drive and major cloud egress pricing, it is still cheaper to buy, ship, and throw away a disk than to send data over the network.
AWS charges 5 cents/GB at the highest tier. That’s $50/TiB (roughly). 18 TiB out from AWS costs $900. You can buy a nice WD Red Pro 18 TiB drive from Amazon for $298, and shipping it next day is not particularly expensive.
Of course, you can’t load data onto that drive from AWS, and you won’t pay anywhere near $900 to send 18 TiB over a network from any reasonable provider.
I think AWS has a similar service where they send a van to your private datacenter that has a bunch of storage servers in it to help you migrate to S3. You plug the van in the network and start uploading.
It's still the case! Upload speeds (especially on consumer-grade Internet connections) haven't kept pace, and AWS will send you box for you to copy your data into that you mail back to them. If you have a lot of data, they'll send you a shipping container!
Around the year 2001 my employer at the time was doing a Exchange mailbox migration from a datacenter in Connecticut to one in Atlanta. They paid for me to fly up there (coach fare), pick up the data on an external USB drive, fly back with the drive in my carry-on luggage, drive to the data center and plug it in.
I knew someone who had to stop by a secure data center on the way home and transport a backup tape to a safety deposit box a block or two away. Not the offsite backups I would have asked for, but that's what they did.
Current LTO drives require to be fed at hundreds of megabytes per second for writing. This is well beyond what 1-gig Ethernet can do. Does you NAS support that?
(You can occasionally get away with slightly lower feed speed -- the drive will write "invisible empty data" to keep the motors running and tape movement going -- but that cuts into capacity of the media in unpredictable ways. And eventually the drive decides it is facing data starvation and stops writing. The result of that is a few seconds of tape repositioning to restart the writes.)
ISTR that tape drive speed divided into the capacity was pretty constant across multiple LTO generations. About three hours to fill a tape, I think.
We used to run "Dell" storage and tape (rebranded ADIC changer and Quantum/IBM drives). A tape changer would autoload tapes under command of the backup software. It would run overnight, automatically changing the tapes two or three times, as required, without issues.
Restore was another problem, mostly the fault of the software.
You would tend to put the tape drive in the NAS, so backup from hosts to NAS over probably slow 1G ethernet, and backup from NAS disk(s) to tape periodically. Not writing from NAS to tape over ethernet, or from hosts direct to tape on the NAS.
Used 10G nics are pretty inexpensive these days, if you really want to write network to tape.
As a hobby, I've looked into second-hand LTO tape backup for my 71 TB NAS but the drive alone is pricey, and if it dies, how can I restore my data without forking over too much money?