• 14 Posts
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Joined 11 months ago
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Cake day: July 24th, 2023

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  • You can also do the following to prevent unwanted writes when something is not mounted at /mnt/thatdrive:

    # make sure it is not mounted, fails if not mounted which is fine
    umount /mnt/thatdrive
    
    # make sure the mountpoint exists
    mkdir -p /mnt/thatdrive
    
    # make the directory immutable, which disallows writing to it (i.e. creating files inside it)
    chattr +i /mnt/thatdrive
    
    # test write to unmounted dir (should fail)
    touch /mnt/thatdrive/myfile
    
    # remount the drive (assumes it’s already listed in fstab)
    mount /mnt/thatdrive
    
    # test write to mounted dir (should succeed)
    touch /mnt/thatdrive/myfile
    
    # cleanup
    rm /mnt/thatdrive/myfile
    

    From man 1 chattr:

    A file with the ‘i’ attribute cannot be modified: it cannot be deleted or renamed, no link can be created to this file, most of the file’s metadata can not be modified, and the file can not be opened in write mode.
    Only the superuser or a process possessing the CAP_LINUX_IMMUTABLE capability can set or clear this attribute.

    I do this to prevent exactly the situation you’ve encountered. Hope this helps!






  • It’s probably best to limit yourself to a used laptop.

    Reading and writing code is nothing more than reading and writing text, and for that you don’t need a fancy gpu or screen.

    What I would recommend you look for in a laptop is

    • an SSD instead of an HDD
    • more cpu cores (at least 4 cores)
    • more memory (RAM) (at least 8GB, preferably 16GB+)

    More memory and cores will help you with compiling and running your code.

    And make sure you take regular backups! You never know when your disk will fail.

    Also make sure to check linux compatibility before you buy. Laptops used to be a pain (10+ years ago), and it’s gotten a lot better, but it’s not always perfect. Just search for “[brand] [model] linux” or try to find the model on the archlinux wiki.










  • Exactly, ansible is basically imperative, where write the steps declaratively.

    Whereas nixos is more like a compiler that compiles to a working linux install.

    If I added the software myprogram and a config file at /etc/myprogram.conf, that’s pretty easy in both. But if I needed to to then remove those it gets different .

    With nixos it’s at easy as removing the two lines that add the program and the config file; after the next “compile”, the file is gone and myprogram is no longer available in the PATH.

    With ansible you need to change the relevant step to use apt remove instead of apt install and to change the config file step in a step that removes the file.

    Don’t get me wrong, ansible is still better than writing a lot of bash scripts, especially if you don’t have people with a lot of shell experience.

    But tools like nixos and guix are on a whole other level.


  • Exactly, if we do a back of the napkin calculation:

    Bitcoin

    Users

    There are 200 million bitcoin wallets, let’s be generous and say those are all owned by unique individuals.

    Total energy consumption

    Bitcoin used about 114 TWh in 2021[1]

    Bitcoin currently uses about 150 TWh annually

    Energy consumption per user

    150 TWh / year 
    ————————— = 0,75 TWh / user / year
    200 million users
    

    Banking system

    Users

    There are over 8 billion people on the planet today, let’s assume 4 billion of them have access to the global banking system.

    Total energy consumption

    The global banking system used an estimated 264 TWh in 2021[1]

    If we assume the same consumption increase rate for banking, that’s about 348 TWh/year currently.

    Energy consumption per user

    348 TWh / year 
    ————————— = 0,087 TWh / user / year
    4.000 million users
    

    With these numbers, bitcoin uses almost 10x the energy per user annually.

    There are of course a myriad of things one can argue over whether it makes a fair comparison, none of which I feel like arguing, since this is just a really simple estimate with a lot of assumptions.

    1: I used the numbers in this article uncritically, if you have better numbers you can run your own calculations.