Linux

I made a custom Linux image to run inside a web browser. No particular distro, just a Linux kernel (compiled with a custom configuration to produce a tiny binary), a shell, and a few small apps.

When reading from the filesystem, it made HTTP requests for each file (+ browser caching), so no need to load a disk image all at once. IIRC, I got the cold boot time down to <1 second (after assets were already cached from a previous load though).

I also got NixOS to run in the browser, but even after stripping out as much as possible, it was still really slow due to systemd. (I'm not a systemd hater, resources are just very limited when running this way.)

I used an x86 emulator called v86. It's a very cool project 🙂

Honestly, im suprised everytime I blindly follow an online tutorial, copying and pasting like a madman, and my hard drive isn't wiped.

When the whole shebang of piping/redirection landed, thinking of all the possibilities!

2 that stand out to me:

When I successfully got virtualbox to boot my windows xp partition inside Linux because I needed to run some software for school.

When I figured out how to use qemu-nbd to mount a qcow2 image backed by a physical block device in order to run non-destructive filesystem repair and file recovery with test disk. Did that for a while for my university IT help desk to quickly save files off failing disks.

I used the aircrack-ng tools to capture wep packets and decrypt my neighbors WiFi because I was broke and needed internet to study back in college..I was a total noob (still am) and when I saw the password in the terminal I felt like I was a total hackerman. It was great!

Once upon a time I was installing Linux on a tiny little laptop, whose brand name I've forgotten. It was probably a Lenovo. Anyway, it was extremely difficult to install anything on it, and they went to great lengths to make sure no one would be able to install Linux on it. I spent an entire day messing around with the grub terminal, and began to suspect that it had a built-in cut off for the USB port during boot. I think I saw some log output to that effect, but I couldn't find any way to disable it. After some thought, I got back in grub, unplugged the USB stick that I was installing Linux from, and plugged it back in. The laptop detected and mounted the external drive and I tried to install again.

Worked perfectly.

Not quite as impressive, but I somehow fucked up something with my bootloader lately and couldn't boot anymore into my main drive. Loaded up a live usb stick and made a new ESP partition, arch-chroot and grub-install/grub-makecfg and it worked again.

Yes, I just followed a guide, but I am still fascinated this just worked on the first try.

If you have binary that is hardcoded to look for some files/libs in a certain path, you can overwrite that path with sed directly lol. You just need to make sure to keep the string length the same.

sed -i s|/usr|././|g will change /usr for the current working dir for example.

In the early 2ks, computer were ugly grey box with noisy fan and a hard drive that gave the impression a cockroach colony were trying to escape your case. I wanted to build a silent computer to watch Divx movies from my bed, but as a broke teen, I just had access to disposed hardwares I could find there and there.

I dismantled a power supply, stuck mosfets to big mother fucking dissipator, and I had a silent power supply. I put another huge industrial dissipator on CPU (think it was an AMD k6 500Mhz) and had fanless cooling. Remained the hard drive.

Live CD/USB weren't common at that time. I've discovered a live CD distrib (I think it was Knoppix) that could run entirely from RAM.

I removed hard drive, boot on live distrib, then replace CD by my Divx and voila.

Having a fanless-harddriveless computer was pure science fiction for me and my friends at that time.

That this worked when I did it in 2006:

wine ~/.wine/drive_c/Program\ Files/Warcraft\ III/Frozen\ Throne.exe -opengl

Moving from old to new Laptop by piping /dev/sda3's content through netcat and into /dev/nvme0n1p3

Piped the ps2 usb camera /dev/video0 to nc. Reverse port fwd'd to my router 200 miles away, and got vlc 200 miles to connect to that port and it worked. No rtsp or server required

Recovered a legacy COBOL 911 dispatch system after the hard drive containing the root filesystem died, which wasn't RAID protected at all and had no complete backups except for a few days prior when I started running daily rsync backups out of paranoia because the idiot dipshit sysadmin who set it all up left the company to work directly for one of our customers.

Thankfully the data volume was RAID protected and didn't die so the critical data was pretty much all there ready to go again after some rebuilding of shit.

Still, took 15 hours to recover. Was a RHEL 4 system when RHEL 6 was current, and we had no way of obtaining the install media or licensing, so I dug up an archived CentOS 4 iso and installed from that, and got stuff working mostly just by copying various files from backup.

Fucking nightmare come true. Drive crashed at noon and we didn't go home until about 4am.

scp

I'm never using a flash drive again.

When the network printer suddenly started printing the picture my kid had drawn in tux paint without me having configured the printer on their PC.

Maybe a little specific, but the first time i used autorandr, I was wow it does exactly what it sounds like it does.

Oh! I just thought of a better one. The first time you run vim scp://user@server//home/user/.

Installing Linux on the Nintendo DS (https://www.dslinux.org/) was pretty impressive for me.

The first time I learned about PDFGrep, I was able to track down a purchase order that would have taken hours otherwise.

I used to be a build engineer at an enterprise Linux company that built custom Linux distributions for various device manufacturers.

I built a whole build automation system that used what would be the equivalent of a Docker container for the build system, and it was distributed across the whole company to make simultaneous build in parallel and a system that would check how many build systems were in use or available with a queueing system.

All written in Bash, Perl and Python.

Oh so many fun adventures, too much to count... But a few nice ones:

• HDD died, so ran a desktop system over network from a NAS (nfs) without HDD.. for months.
• Rebuilding a corrupted system (any bit advanced tools wouldn't start anymore, like apt).
• Custom bootable live cd based on Linux From Scratch (around 2002).
• Anything related to Kerberos and NFS4.
• Replacing syscalls to run software from a ramdrive that would otherwise not work.
• Recently using debootstrap to install Kubuntu with a ZFS root, which went surprisingly smooth and pretty easy.

I love Linux for all these insane possibilities.

mdadm

Migrated a server to a new drive by copying all the files with rsync and chrooting into it. Nothing too impressive from a linux standpoint, but I had no idea that was possible until I tried it.

I tripped over a cord once and broke the screen on my laptop. I salvaged the disk for another purpuse. But I got some prime hardware here, it's got video output, it's got ram, and a cpu! I used it for my lectures; liveusb with some persistent storage on, put my slides on there and fire it up. Did not have to unplug the normal laptop from my office. Nothing magic really, but some students were puzzled.

Disabling CPUs by writing a zero to some file under /sys

Probably installing a different kernel and adding it to systemd boot manually a while back.

Oh and the very first was most likely installing Arch manually.

Random one recently:

Turned my gaming box into an impromptu audio mixer by connecting my PS5 audio into the line in and routing it with pipewire to the speaker output so I could game while watching endurance racing on the same speakers.

Later found it was easier to do visually with qpwgraph.