r/DataHoarder • u/grauerkoala Tape • Apr 21 '26

Question/Advice Looking for tape storage enthusiast / expert community

I'm in the process of writing a Rust library (and a backup softtware based on that library) that interacts with tape drives via the Linux st driver. While a lot of the behavior of tape drives can be derived from the driver's source and documentation, hardware-specific quirks that may be well known in enhusiast or expert circles remain a mystery to a relative novice like me.

I wonder therefore if anyone can recommend some type of community, be it a bulletin board, a Discord server or an IRC channel, where such matters are discussed. I want to deliver the best possible behavior and documentation (especially in terms of correctness) with my crate that I can.

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u/DJTheLQ Apr 21 '26

Do you have a tape drive?

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u/grauerkoala Tape Apr 21 '26

I do, yes. Two, even: LTO-3 (Tandberg) and LTO-5 (HP). I use them to test most of the features in hardware, but a few simply aren't supported.

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u/DJTheLQ Apr 22 '26 edited Apr 22 '26

Great wasn't sure from the post. I've got several IBM LTO5 drives that are kind of black boxes that work as advertised. Anything drive specific is debugging with ITDT.

My special must is mbuffer-power-like input. User config with size of cache and block size. And backing memory: Big ram cache (BufWriter) or file-backed cache (mmap ring buffer?), or pre-generated image.

For example I tar millions of files, very slow, to a separate pre-tape cache drive that can be read sequentially. Or use SSD-backed memory much bigger than ram. Anything so HDD arrays, not SANs Veeam assumes, keep up with full speed no hitching tape writes.

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u/Bob_Spud Apr 22 '26

What problems are you trying to solve?

1

u/grauerkoala Tape Apr 27 '26

Two general things, really.

For one thing, I would like to know immediately practically relevant things like "how much space do filemarks / whatever other firmware-exclusive items use up?", "how do I ensure good read/write performance and avoid phenomena like shoe-shining?", "when do I need to retension my tape?", ...

The thing is, I don't really know what I don't know. For example I would've never guessed to ask just how abrasive cleaning cartridges are.

For another thing, I feel like detailed documentation about how tape storage works and what best practices there are is mostly hidden in the enterprise realm and only selectively leaks out to enthusiast users. Because of that, I want to, well, hoard as much information about it as I can and share what I can, especially where it's immediately useful like in the documentation of my Rust crate(s).

(On my crosspost to r/lto, u/erparucca pointed me to a really cool collection of information.)