Something not mentioned by the author, but what I was told here on Hacker News some years ago: If your drive has too much wear (or misalignment of the drive head?) you might end up with tapes that you can only read with exactly your drive.
That's something I've seen mentioned too but never could verify if that is something that's actually true with modern tape standards or not. (i.e. last I asked on HN I was told it wasn't a concern anymore) If the drive needs to adjust to get precise enough positioning anyhow, misalignment seems way less likely.
It's absolutely true. There is a LOT more to tape storage than meets the eye.
Let's say you're using LTO tapes as an archive. Did you know LTO tape itself is abrasive, but that abrasive is meant to wear over time with the intended use of the cartridges, which was backups?
If you use new tapes a single time, the abrasive doesn't wear and destroys the tape heads. You will go through a drive head at month, running the drives 24/7. I had a library used as a genomic storage archive with 8 drives (always write, almost never read), and two were constantly out of service, as we averaged two head replacements from IBM a week.
This is much less a factor on use tapes that have been run through a drive a few times.
I worked for an LTO tape drive manufacturer for 20 years, and I never heard about this. I think something else was at play here, although I could be wrong. The drives are often used just as you did, although perhaps not always as intensively. Data is written to tapes, and they are shipped offsite. Basically, WORN (write once read never). The backups are for an absolute emergency, such as a 911 type event where a whole building comes down or a data center burns to the ground.
A few factors which may have influenced what you experienced:
* The quality of the tapes could be variable. In my experience, some branded tapes were significantly inferior to others.
* If the drive ran hot, then that may have contributed. IIRC, IBM's LTO-3 drive ran very hot.
* If you don't write data to the tape fast enough, it won't stream. It'll shoe-shine back and forth, as it runs out of data, repositions backwards on the tape, and resumes writing. I think this might affect the tape head life.
These were IBM drives in a QualStar XLS connected to systems running FileTek StorEdge. I don't remember if these were Fuji or Sony tapes, but I think Fuji, branded Fuji.
We did have shoeshining issues in testing, but increasing the amount of caching fixed that. Never heard of any throughput issues in production, but .. .edu so you know how well we monitored. That was a software issue anyway.
I think it was LTO5 era, but I don't rightly remember.
The IBM dude who handled all the hardware support would take a look at everything, nod, and replace the drive. I took him out for beer once and that's when he told me about the issues with the tapes. I left for greener pastures before that was solved, but it was going on for a good year.
Maybe he liked the food trucks outside the building, or maybe it was cheaper for them to replace the drives than actually help us fix the problem. Anyway, thanks for the insight! Glad I don't work on hardware anymore.
I've not seen it on LTO. Where I work we either had very large tape libraries, with 25+ drives in. We didn't have drive affinity, so if that happened I would get an alert.
The other team used to import bulk data by receiving tapes from all over london and beyond, there must have been thousands of drives writing and reading that data. Plus we didn't buy fresh tapes, and they were dropped, thrown, left in the cold/sun, all sorts.
But that's different than "drive will produce tapes that it can read, but other drives don't"? Because sure, drives can fail and need service/replacement, but that's less insidious than a drive producing tapes that are silently unusable in other drives.
The gist is that HP heads were harder material than IBM heads and if you used alot of out-of-spec abrasive MAXELL tapes, especially always fresh ones, then on IBM drives, the drives would suffer from premature "pole tip recession" and could no longer read or write any tape. HP drives seemed less affected.
To find out what manufacturer made the tape, you had to insert the tape into a drive and read the MAM chip over SCSI/SAS. With tapes basically everyone did alot of rebadging, so if you got a "HP" tape it could be anything from MAXELL to Sony to Fujifilm. "IBM" tapes were usually Fujifilm, i.e. good to use everywhere.
That was true before embedded servo tracks (why the author mentions you cant bulk erase LTO tapes), its not been true for ~20 years unless one was using DLT, DAT, etc.
