> You need some way to make sure the data on the tape matches the original after writing.
Do you? Virtually every filesystem has some kind of error detection, maybe even error-correction built in.
That seems like a solved problem to me. CD-R solved this by writing Reed-Solomon codes every couple of bytes so that if any error occurred, you could just fix them on the fly. (As such: you could have scratches erase all sorts of data, but still read the data back just fine)
I have to imagine that tapes have a similar kind of error-correction going on, using whatever is popular these days (LDPC?). Once you have error correction and error detection, you just read/write as usual.
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If Tapes don't have that sort of correction/detection built in, you can build it out at the software level (like Backblaze used to do)... or maybe like Parchive (https://en.wikipedia.org/wiki/Parchive).
> Virtually every filesystem has some kind of error detection, maybe even error-correction built in.
Nitpick: you mean physical encoding, not filesystem.
Not nitpick: it’s nowhere near enough. Blu-Ray bitrot is a huge issue and if you don’t either write out your data twice (to the same disc or to distinct discs) or use PAR2 or similar, your backup isn’t worth the money you paid for those shiny coasters.
Yeah I’ve written about those on here before. I bought some but haven’t had time to use them; I’ve read anecdotal reports of them not lasting any longer than regular HTL (instead of LTH) discs.
par2 even has options for specifying level of redundancy. I've had good experience in recovering large corrupted files from an external drive - since then, I've incorporated it into the automated backups of my personal infrastructure.
Do you? Virtually every filesystem has some kind of error detection, maybe even error-correction built in.
That seems like a solved problem to me. CD-R solved this by writing Reed-Solomon codes every couple of bytes so that if any error occurred, you could just fix them on the fly. (As such: you could have scratches erase all sorts of data, but still read the data back just fine)
I have to imagine that tapes have a similar kind of error-correction going on, using whatever is popular these days (LDPC?). Once you have error correction and error detection, you just read/write as usual.
-------
If Tapes don't have that sort of correction/detection built in, you can build it out at the software level (like Backblaze used to do)... or maybe like Parchive (https://en.wikipedia.org/wiki/Parchive).