• 8 Posts
  • 986 Comments
Joined 1 year ago
cake
Cake day: October 4th, 2023

help-circle



  • There’s an already-extant ground-based vessel navigation system, Loran-C, though I’m sure that it’s possible to improve on it and I have no idea how much of the receiver hardware is still out there.

    https://en.wikipedia.org/wiki/Loran-C

    The introduction of civilian satellite navigation in the 1990s led to a rapid drop-off in Loran-C use. Discussions about the future of Loran-C began in the 1990s; several turn-off dates were announced and then cancelled. In 2010, the US and Canadian systems were shut down, along with Loran-C/CHAYKA stations that were shared with Russia.[2][3] Several other chains remained active; some were upgraded for continued use. At the end of 2015, navigation chains in most of Europe were turned off.[4] In December 2015 in the United States, there was also renewed discussion of funding an eLoran system,[5] and NIST offered to fund development of a microchip-sized eLoran receiver for distribution of timing signals.[6]

    The National Timing Resilience and Security Act of 2017, proposed resurrecting Loran as a backup for the United States in case of a GPS outage caused by space weather or attack.[7][8]



  • I’m sure not, but even without looking at any technical details, it will have at least a couple benefits:

    • First, it’s short range. GPS satellites are in geosynchronous orbit, which is a pretty high orbit. Wikipedia says about 22,000 miles away. For GPS, the jammer is going to be far closer than the legitimate signal.

    • Second, I’m guessing — though we’ll see — that this is going to be a civilian system, and I suppose that they could even try to mandate that militaries not use it. GPS was, from the beginning, a military system, and there are weapons being used in Ukraine that use it for guidance. Unless you’re solely out to be a dick — which isn’t impossible — probably not a lot of benefit to stomping on civilian-only frequencies.







  • Italy is using its Piracy Shield law to go after Google, with a court ordering the Internet giant to immediately begin poisoning its public DNS servers

    I don’t know why Italy is wasting time on this.

    Italy is not going to be able to force all public DNS servers out there to block things that they want blocked. Anyone using Google’s DNS servers is already going out of their way to use an alternate DNS and can probably plonk in another IP address if they want. It’s not as if Google has the only publicly-accessible DNS server out there.

    If Italy really and truly doesn’t want a DNS server that is doing this to be accessible in Italy, go after Italian network service providers, and instead of playing a never-ending game of whack-a-mole until they run into someone who just tells Italy to buzz off, just block it. Now, some portion of Italians are probably going to still get to DNS servers that ignore Italy’s views on things via VPNs unless Italy wants to ban those too, but it’d at least be more-effective than trying to go after every DNS server provider out there, which is definitely is going to leave DNS servers that don’t block sites accessible online.

    Frankly, I don’t even think that DNS-based censorship is very effective in the first place anyway, but if you’re going to do it, might as well at least do it as effectively as possible.


  • Vidoc posted on local job boards, like the one in Poland. But whoever was behind this operation figured out that it’s profitable to pose as Serbian, Polish, and other eastern European profiles

    I’d think that this could be pretty easily resolved by just having a real-life interview, at least for the final interview.

    It sounds like Vidoc is in Poland. Maybe it’s just me, but if I were being hired for an engineering position, I’d think that it’d be reasonable to be willing to travel to a final interview, and for the company to cover any costs.

    But, okay, say that it doesn’t make sense. Maybe the finances don’t work, maybe they want to hire from somewhere where it’s not practical for people to travel to their location. I’d think that it’d be possible to have an “interviewing company”. That company just obtains some office space, sets up videoconference conferencing rooms, and has their own trusted cameras and suchlike present.


  • Would you advice to have such a large swapfile

    On laptops, you normally want at least as much swap space as you do physical memory, as when you hibernate the thing, that’s where the hibernation data is stored, and if you don’t have enough space there, hibernation will fail. IIRC, it’s also required for some kernel debugging technique (where, as hazy memory indicates, I believe the kernel can basically “dump core” to swap space, then reboot and write it out to regular storage). So it certainly works, because there are a lot of Linux systems out there that use that much relative to physical memory. Though I admit that I’ve never tried using a swap file instead of a swap partition, myself.

    It’s not quite like the old days, with rotational drives, and pre-OOM killer, where having a huge amount of swap would let the system bog down to the point where it couldn’t be used.

    Do you need 32GB swap? Probably not, if you don’t plan to hibernate the system. But unless you need the storage for something else, probably doesn’t hurt. And if you’ve got a 1TB system drive, I doubt that you’re short on space.

    I have 128GB of main memory and 128GB of swap on this system. Same 1:1 ratio, and I normally use that on Linux systems.

    For the example, I just chose an arbitrary, “reasonable” size. Feel free to pick a size that you feel is better, if you’d prefer something else.


  • tal@lemmy.todaytoLinux@lemmy.worldPerformance tanking during swapping
    link
    fedilink
    English
    arrow-up
    6
    arrow-down
    1
    ·
    edit-2
    12 days ago

    In the sysstat package, there’s a command, iostat, that shows the amount of time that the average CPU (core) is waiting for something.

    avg-cpu:  %user   %nice %system %iowait  %steal   %idle
               0.57    0.01    0.55    3.14    0.00   95.73
    

    “User” is the CPU time used by regular processes. “Nice” is the time used by “niced” processes, stuff running at low priority. “System” is time used by the kernel. “Iowait” is the time waiting for I/O operations to complete.

    If you’re bounded on I/O, then the iowait number is probably going to be relatively high.

    It’ll also show you I/O load on each device (and the sysstat package can log this over time, let you use sar to see historical numbers).

    You can artificially induce load on a given I/O device to see whether load on it induces your problem. Something like this:

    $ dd if=/dev/zero of=filename-that-you-want bs=1M
    

    That’ll start your system just writing zeroes to a file. If it’s I/O contention on the mSATA drive, then I’d expect you to see the problems you mentioned.

    One thing you might check is whether your system is logging errors during this time. I don’t know what a failing SSD looks like, but in my experience a failing rotational drive would often see errors and then attempts to re-perform I/O operations. That produces seriously-degraded disk I/O performance. These errors will show up in the kernel log. To see kernel errors since the current boot:

    $ journalctl -kb
    

    The smartmontools package contains a command, smartctl, which will let you see what your drive thinks of its own health. I’m not really familiar with what a failing SSD would look like, but with rotational drives, it can indicate that something’s wrong with the drive, and it looks like my SSDs do report SMART status.

    # smartctl -a /dev/sda
    

    Moving swap

    Linux can, if it needs to, use a swap file instead of a swap partition, so you don’t need to repartition your NVMe if you just want to try putting your swap on the NVMe.

    If you want to, first, for the current boot, disable all the active swap partitions.

    # swapoff -a
    

    If you run top, you’ll see the available swap be at zero.

    Then you want to create the swap file. Say we drop it in /var:

    # mkswap --file /var/swapfile --size 32GiB
    

    And then you can enable it:

    # swapon /var/swapfile
    

    Then see how things perform.

    If it makes your problem go away and you want to make the change persistent:

    In /etc/fstab, you’ll have a line for your swap partition that the system reads at each boot. Will probably look something like this:

    /dev/mapper/system--vg-swap_1 none            swap    sw              0       0
    

    Comment that out by sticking a “#” at the beginning of your line, and put a line in for your new swapfile on the NVMe:

    /var/swapfile none            swap    sw              0       0
    

  • Combating “Skynet”-level threats

    During the experiment, the professionals were faced with a typical national security threat: A foreign government interfering in an election in their country. They were then assigned to one of three scenarios: a control scenario, where the threat only involved human hackers; a scenario with light, “tactical” AI involvement, where hackers were assisted by AI; and a scenario with heavy levels of AI involvement, where participants were told that the threat was orchestrated by a “strategic” AI program.

    When confronted with a strategic AI-based threat — what Whyte calls a “Skynet”-level threat, referencing the “Terminator” movie franchise — the professionals tended to doubt their training and were hesitant to act. They were also more likely to ask for additional intelligence information compared with their colleagues in the other two groups, who generally responded to the situation according to their training.

    That’s a human-level (well, superhuman) AGI. I don’t think that we have a good handle on what the limitations or strengths would be. I’d try to gather as much information or thoughts from others as I could too.

    In the same vein, if someone gave me a scenario where they said “You’re facing a demonic necromancer. How do you counter them?” I’d probably be a lot less confident about how to act than if they said “you’re facing someone with a pistol”, because this is kind of out of the blue, and I don’t even really understand the nature of the threat. There’s no AI there, but it’s a novel scenario with a lot of unknowns, and it’s not as if I’ve read through histories of how people dealt with that or recommended doctrine for that. I don’t think that it’s the AI that’s so much the X factor here as it is the sheer degree of unknown factors that show up.


  • If you’ve already got a VR headset and you’re happy with it, I’m envious. But for the rest of us, it’s worth asking the question: just what is it going to take to get on board?

    Speaking for myself, if I can use a headset about as well as I do a regular display, that’ll do it for me. I’m less-interested in a gaming-specific peripheral, though that’d be nice frosting on the cake. If I can just carry a headset in a case and a display-less laptop, that’d probably be sufficient to get me onboard the HMD train.

    There are real benefits to that:

    • Privacy. My screen isn’t visible to anyone nearby.

    • Wider field of view possible.

    • No glare issues.

    • Potentially less power use, since one isn’t blasting light everywhere just to get a little into one’s eye.

    • Able to use in any orientation easily, like lying down.

    My experience so far has not led me to believe that this is near. I’ve found HMDs to be twitchy about the location relative to the eye, prone to blurriness if nudged a bit off. Blurriness around the edges. On my Royole Moon, fogging up is an issue, due to shields to eliminate light from bleeding in. Limited resolution. For some, inability to easily see the surrounding world. Limited refresh rates. Many headsets can’t really be used with headphones, which is okay, as long as you’re fine with the headphones that come with the headset. [EDIT: As someone else pointed out, setup time is a hassle as well. I want using one to be as trivial as it is today for me to open my wireless headphones case and throw the headphones on my head, with just the addition of a cable.]

    I don’t personally really care all that much about price, if the thing can serve as a competitive monitor replacement, since then it’s not just a toy.

    I’d also add that I think that there are some genres, like flight sims, where VR has legitimately succeeded. Like, compared to multiple-monitor rigs that some serious flight sim fans have set up, VR is pretty much better in all ways. No physical control panels and such, maybe, but they really want the wide FOV and ability to use the head/eye as an input device.

    I’m sure that there are probably some AR applications where you can find an AR headset making sense. Maybe stargazing or something.

    But what the article author seems to want is a transition to a world where basically all or a large chunk of new video games are VR-based. And yeah, that hasn’t happened.

    EDIT: Honestly, most of the games I find myself spending a lot of time playing aren’t even 3D in the first place. That’s not due to lack of hardware. I have a pretty maxed-out PC, can run them fine. It’s just not what I think is most-entertaining to do — many of the games that I find really deep and replayable are 2D, so I’m not playing the 3D games that I do have. If the games aren’t 3D, it’s hard to see how VR buys much.



  • tal@lemmy.todaytoLinux@lemmy.worldFtp mounting doesn't seem to work
    link
    fedilink
    English
    arrow-up
    2
    arrow-down
    1
    ·
    edit-2
    14 days ago

    I haven’t ever used curlftpfs, but I imagine that if this is the problem and if Fedora doesn’t have a fix, it’s probably possible to build it out of tarball and use a wrapper around curlftpfs as a temporary workaround. It doesn’t look like curlftpfs lets you specify the path to the curl binary, so probably need to modify PATH prior to invoking curlftpfs.

    Like, something along the lines of:

    • build curl 8.8.0 from tarball, stick curl binary in directory (say, in /opt/curl/)

    • Create curlftpfswrapper.sh:

        #!/bin/bash
        export PATH=/opt/curl/:"$PATH"
        exec curlftpfs "$@"
      
    • Drop curlftpfswrapper.sh somewhere in your PATH.

    • Use curlftpfswrapper.sh instead of curlftpfs as long as it’s broken.