Dead USB Drives Are Fine: Building a Reliable Sneakernet • Hacker News Board

Re: Dead USB Drives Are Fine: Building a Reliable Sneakernet

#81

Post by O__________O » Mon, Sep 05, 2022, 11:04 AM UTC

myself248 wrote: post #74

O__________O wrote: post #68

Earlier quoted context omitted.

For clarification, all USB ports are 5 volts DC; transformer (or computer) will take care of converting the 120/220 AC current to the necessary 5 volts DC. Commonly two types of isolation data and power chipsets. For a dead drop, you would want a cheap voltage isolator set to trip/blow a fuse at 5 volts DC — with no data isolator.

What? So what do you do if someone puts 120 volts on the data lines? You very much want to isolate both. Which is precisely the function of the chipsets I mentioned.

Data chipset blocks all data flow - whole point of connecting to the deaddrop is to get data; and yes, I agree all lines when capping voltage show be checked, though would not be surprised it’s not common for off the shelf usb power isolators to only check the power lines as defined by USB standards.

Re: Dead USB Drives Are Fine: Building a Reliable Sneakernet

#82

Post by jgoerzen » Mon, Sep 05, 2022, 6:54 PM UTC

ytjohn wrote: post #50

trasz wrote: post #6

It’s cool and sounds like reinventing UUCP. Which has the advantage of serving as a transparent transport for ordinary email.

http://www.nncpgo.org/Comparison.html This is really amazing stuff. Years ago, I was heavily interested in scuttlebutt [1]. I'm interested in grid down and "occasionally connected" communications. I particularly liked the island to island sailing analogy. SSB has a few downsides - mainly that your client needs to download full logs. You can't just request the last 30 days. They call this out as well that your first s…

You may be interested to note that NNCP integrated Yggdrasil support recently (though you can also run Yggdrasil at the OS level). Yggdrasil is an always-encrypted IPv6-based mesh, and is a perfect fit for something like ad-hoc wifi (since the nodes can discover a route to each other based even on RF paths).

Yggdrasil can also run as an overlay network atop standard Internet (IPv4 or IPv6), or both. It will opportunistically find peers on a local broadcast domain and find routes to other networks over the standard Internet if need be.

Feel free to drop me a note if you like; I had a very similar experience with SSB. NNCP, while it has a bit of a learning curve, Just Works. It processes thousands of packets for me every day (hourly ZFS snapshot backups for every filesystem I have), some of which are huge, and it Just Works.

Re: Dead USB Drives Are Fine: Building a Reliable Sneakernet

#83

Post by 0xbadcafebee » Tue, Sep 06, 2022, 4:12 PM UTC

digikata wrote: post #70

0xbadcafebee wrote: post #63

Earlier quoted context omitted.

I'm sure you can come up with abstractions, but without first doing a whole system design (FRs & NFRs, mapping dependencies, customer requirements, etc) you'll have to scrap those abstractions when they don't match up with how the system ends up needing to operate. So I would recommend not even thinking about technical abstractions until you have a very large multi-layered system visualization. For example: what is s…

These are fair suggestions for the low level detail of my comment. I think the core functionality is providing a web friendly storage access api providing for user control and syncing between multiple nodes. It's been done before but not recently with more recent and lighter protocols. Apps like the classic sample todo or note taking apps frequently shown on HN should really just be able to connect to a user owned st…

> Apps like the classic sample todo or note taking apps frequently shown on HN should really just be able to connect to a user owned storage - get authorized for a stoage allocation either fronting local storage or easy to spin up a node on a cloud hosted vm.

Let's think of the simplest possible implementation of that.

A todo app wants to write to 'your storage'. What are your options for storage? If it's some thing like Google Drive, that is a proprietary interface, so right off the bat, you are now implementing vendor-specific things, so an abstraction is not worth much. You could make some kind of "JavaScript Framework For Storage", aka a js library that has 50 different proprietary implementations, but that would only work for javascript apps. Which, if you only code in JavaScript, is fine, but if you want to support some other application written in another language, now somebody has to maintain those 50 different proprietary implementations in another language too. That's just not sustainable.

If instead you want to create one standard web API to access storage through, even if you could define exactly what it should do, you now need to get Google to implement that one standard web API. But why would they? They already have their own Google Drive API which works perfectly well for their own purposes. You would have to show them some significant business advantage to throwing away all the money and code they've sunk into their own API (not to mention that all their customers and their apps have sunk into it) and build and adopt this new API. (That assumes you could even get them to agree to whatever standard API you created, as they may want a half dozen extra features that have nothing to do with storage)

By modeling the whole system, you can quickly see all the weird quirky problems that you will run into trying to make this API and get it adopted. It's not impossible, but it's a much larger problem space than you imagine at first.

Re: Dead USB Drives Are Fine: Building a Reliable Sneakernet

#84

Post by bitwize » Tue, Sep 06, 2022, 6:40 PM UTC

non-nil wrote: post #3

Being a teen in the 90s, sneakernet was sometimes even more fascinating and exciting to me than internet connectivity. It had an air of secrecy to it, little bundles of precious data carried between a select group of people on various, often cumbersome and/or expensive storage media. When everything is connected by a bunch of wires, it’s just too easy. Sometimes I wish for a return a that feeling of preciousness, ins…

I feel you. In the 90s I came into possession of a strange floppy disk with this on the label:

    Dear Friend,

    Please tell my story.

    Sincerely,
    Dave Koresh

After doing a thorough virus scan, I examined the contents of the disk. It contained a bunch of stories and essays by various authors in text-file format, nothing dealing directly with David Koresh or the Branch Davidians.

But the FBI raid of the Branch Davidian compound in 1993 caused... unrest in certain pockets of the American politisphere, primarily on the right but groups like the ACLU also got involved, and Janet Reno was mocked on SNL for her role in the incident. Nobody liked the Branch Davidians, they were a weird-ass cult preparing for an apocalypse that never came except maybe in a parrot sense[0], but there were concerns that the FBI (and potentially the ATF before) acted too aggressively, overstepping legitimate law-enforcement bounds and violating the Davidians' rights, and that caused a lot of political introspection: on our status as a freedom-respecting republic, the competence of our federal law-enforcement apparatus, what is the threshold beyond which the government legitimately could or should take action against weird-ass prepper cults. So there was a lot of philosophy and politics stuff in there, often in the form of USENET postings and other 90s internet copypasta, that dealt tangentially with those issues.

It felt... kind of weird and awesome to have and to read that stuff. Cyberpunk. Here were thoughts that people felt not quite safe transmitting or discussing openly, so they were copied and distributed as floppy-disk samizdat. It was a mysterious object, alarming at sight because it suggested that Koresh might still be alive somewhere (and the shortening of "David" to "Dave" made him seem... humbled?), whose contents held even deeper and more thought-provoking mysteries.

[0] "I heard tell once of a Jefferson City lawyer who had a parrot that would wake him each morning crying out 'today's the day the world shall end as scripture has foretold'. And one day, the lawyer shot him for the sake of peace and quiet I presume, thus fulfilling, for the bird at least, his prophecy." -- Daniel Day Lewis as Lincoln in Lincoln (2012).

Re: Dead USB Drives Are Fine: Building a Reliable Sneakernet

#85

Post by myself248 » Tue, Sep 13, 2022, 11:37 PM UTC

O__________O wrote: post #81

myself248 wrote: post #74

Earlier quoted context omitted.

What? So what do you do if someone puts 120 volts on the data lines? You very much want to isolate both. Which is precisely the function of the chipsets I mentioned.

Data chipset blocks all data flow - whole point of connecting to the deaddrop is to get data; and yes, I agree all lines when capping voltage show be checked, though would not be surprised it’s not common for off the shelf usb power isolators to only check the power lines as defined by USB standards.

No.

No, no, no.

A USB data-line isolator does not block data flow. Its entire purpose is to alow data to be communicated across a galvanically-isolated gap. It uses magnetic (transformer) or optical isolators to do that.

It blocks POWER flow, while passing data. Look up the ADUM3160 datasheet.