8mo ago

What're some of the dumbest things you've done to yourself in Linux?

I'm working on a some materials for a class wherein I'll be teaching some young, wide-eyed Windows nerds about Linux and we're including a section we're calling "foot guns". Basically it's ways you might shoot yourself in the foot while meddling with your newfound Linux powers.

I've got the usual forgetting the . in lines like this:

 undefined

    
$ rm -rf ./bin

As well as a bunch of other fun stories like that one time I mounted my Linux home folder into my Windows machine, forgot I did that, then deleted a parent folder.

You know, the war stories.

Tell me yours. I wanna share your mistakes so that they can learn from them.

Fun (?) side note: somehow, my entire ${HOME}/projects folder has been deleted like... just now, and I have no idea how it happened. I may have a terrible new story to add if I figure it out.

301 comments

Running the right command on the wrong SSH session/machine.
- This is the scariest comment I've read in this thread.
  
  Imagine that you’re using fqdns instead of ips…
  I refuse to elaborate.
- I set a different background color on all my machines because of exactly this while using VNC/RDP
  
  this. after i set different zsh themes on my servers + my main machine i now know exactly what machine i’m running commands to
  
  Neat idea, I hope I'll remember this when I'm setting up my next server.
- You are not alone.
- Me every single day

I wanted to try inserting and removing kernel modules, so I looked around and thought "well, I don't have a USB stick in right now so I can safely try removing the usb kernel module." So I did that, and after pressing enter I realized my keyboard is connected with USB.
- I was smug thinking "I haven't done anything so silly as the people commenting in this thread", then I came across this one. I've actually done this one, and it was earlier this year, and I've been using Linux since 2004, 20 years.

have an nvidia GPU
have Fedora
download RPM package of drivers for Red Hat (after all, Fedora and Red Hat are... compatible, right?)
Everything goes fine
Six months later, upgrade to a new version of Fedora
oops, kernel panic at boot after the upgrade, and no video to troubleshoot after UEFI boot
figure out how to boot into a recovery partition from UEFI
figure out how to enable a serial console over a USB device
figure out how to connect to the serial console from another computer using another USB device
figure out what the kernel panic is from (not the upgrade, but the driver which wasn't upgraded)
figure out how to uninstall the incorrectly installed driver
figure out how to install the correct driver
That was a fun three week OS upgrade.
- I have a super-n00b question, and I apologize in advance, but, uh...yeah, what is a serial console?
  
  Tl;dr: Stick in a USB cable and the other side gets your console.
  
  You attach a secondary computer via serial (COM port) with your primary computer and then you can open a console on that one. You can access the primary computer as if you would be sitting in front of it.
  
  Adding to what DmMacniel said, it's a hardware interface, often accessed via a USB port (which after all, is the universal serial bus).
  
  https://en.wikipedia.org/wiki/Serial_console
  tl;dr:
  Serial ports are (for example) commonly RS-232, although other types of ports exist. Imagine it to be a very slow Ethernet device. Because it's so slow (and the technology predates Ethernet and also has different requirements), it's usually attached directly to a device instead of to a network. But you could connect a modem to it and it becomes connected to a network device.
  It could also be connected to a system console device. These are commonly called terminals. Such devices are often monochrome (especially older ones) because a serial connection is often bandwidth limited (eg, measured in kilobits per second instead of megabits or gigabits). Since it's so slow, it's not practical for video, so it's generally just text-only.
  Note that your GPU might also output a system console but rendered on your display at very high resolution and with graphics-drawing capabilities. So a system console would be any console that connects to the system.
  What is a console? Well, Wikipedia presents several valid articles and the common theme as far as computers go is that a "console" is typically something that a human and a computer use to interact with each other.
  For serial consoles, you might find device files for them at /dev/tty*. But for general serial devices, it could be any of several different types of device files.
  Wikipedia's article on /dev devices has a pretty decent listing of what kinds of devices you might find and several of them might be classified as a serial port. Any serial port might be connected to a serial console.
  So in my case, a serial console is:
  2x USB-to-RS-232 (USB is a serial protocol and is basically "just" another (Universal) (and perhaps high speed) Serial port (Bus), so conversion is super cheap)
  1x RS-232 null modem cable
  That's pretty much it in a nutshell. Then
  System 1 (the failing system) UEFI boots into repair system partition on a separately attached disk (eg, boot from CD or live USB) to get a local system console
  System 1 repair system mounts the failing system partition
  System 1 modifies failing system grub configuration to enable a serial console on the attached USB-to-serial device file and saves changes, then unmounts failing system partition
  Power off System 1
  Remove repair partition device
  Open terminal window on System 2 (recovery system)
  Connect System 2 terminal to the attached USB-to-serial device file using screen (oh wow those were some old days)
  Power on System 1
  System 1 boot enters grub recovery menu which allows fixing the system remotely
  To be fair, a lot of that complexity could have been done by either reinstalling, or removing the hard drive and attaching it to another computer. But doing it this way allowed me to poke around and try different ways of solving the issue, rebooting, etc. It was a learning experience worth exploring.
  It was years ago though and I think there was some complication with trying to understand what device file (or device number or something) needed to be to work on the correct serial device (there are often multiple)
- Why would you need a serial console? Live USB is a thing

I tried to install an OS to a USB stick. This is Kubuntu specific.
You need to create a GPT partition on the stick, then you should be able to just use the installer and install on another USB stick.
I went through it, selected the usb stick... was not sure if everything was right and went a menu back, was correct, went forth again, past the install target selection and installed.
Well... turns out the Kubuntu installer (Calamares) selects the first disk always. And that selection seems to reset to default when going a menu back....
I deleted my complete normal disk, with like everything I had.
No Backup no mercy. Luckily did one only a few weeks before. The first since half a year! Damn... had my uni stuff on Nextcloud, a lot of personal stuff synced to my phone with syncthing.
- I was gonna recommend kubuntu for a first time user, seems a bit of a hassle then doesn't it?
  
  I mean if you actually want to overwrite the main SSD this is okay. Calamares is very nice too.
  Kubuntu stays on Plasma 5 forever so I highly recommend against it. There are many bugs that will not get fixed, the fixes are only in Plasma 6.
  I recommend Fedora Kinoite. Use Flatpaks, layer the packages you dont need. Add rpmfusion and layer libavcodec-freeworld to get video playback working.
  I broke all KDE distros, Kubuntu included. I wouldnt use anything other than Fedora Kinoite, nor want to maintain that mess. Have a look at my latest post for some explanations.

rm *.c when I meant rm *.o

ntfsclone /dev/sdc /dev/sdb
/dev/sdb was a blank filesystem and /dev/sdc was my Windows filesystem.
ntfsclone man page
It ran for less than a second and didn't take me long to figure out what happened. That's the story of how I stopped using Windows.
- Damn that's the equivalent of going cold turkey.
- I don’t use windows for close to 20 years so I didn’t need ntfsclone so far but do I read correctly the man page that only the source is specified as positional parameter? If so, shouldn’t you have to write
  nftsclone —overwrite /dev/sdc /dev/sdb? It still can be misleading (given that mv uses two positional parameters so mv -f source destination would have done what you wanted) but a bit less cryptic?
  
  Yeah, sorry it was a long time ago (like 10+ years) but I checked and it would've been the --overwrite arg.
  The manpage for the older ntfsclone command has it:
  Clone NTFS on /dev/hda1 to /dev/hdc1: ntfsclone --overwrite /dev/hdc1 /dev/hda1
  Moral of the story was to RTFM 😂

If you count Android too, then this: I got my first Android phone when I was 10 or 11 and rooted it on the first day of having it. This was during a time when we were all still using ClockworkMod because TWRP didn't exist yet, and I somehow ended up with a system without a kernel. Panic ensued, and I spent that entire night (like 10 hours) digging through xda in order to find a tutorial on how to get this damn phone to run again. Imagine having to tell your parents "I broke my phone I got yesterday." I did get it working at like 6:30 AM. Fun times.
- what's the fun in modding if not the two hours where you think you've bricked everything and you're scrambling through a 52 page post on XDA trying to find someone with your same problem
- I did pretty much exactly this on a Galaxy S1 (i9000) that was old even when I got it, but my uncle who gave it to me said that to make it usable I needed to install Cyanogenmod.
  I thought I fully bricked the phone trying and it actually sat dormant for years afterwards until I re-found the Odin backups I had taken, and was able to fully fix and restore it. Unfortunately by that time, nearly no ROM existed that was both up to date and a usable speed.
- Oh man,, Clockwork mod, that takes me back. Although I had my android phone for a while before I built up the courage to root it, in part due to stories like yours

An older friend of mine told me years back about an incident that happened on a university VAX running Unix. In those days, everyone was using vt100 terminals, and the disk drives weren't all that quick. He was working on his own terminal when without warning, he got this error when trying to run a common command (e.g. ls)
undefined

$ ls -l sh: ls: command not found
So he went on over to the system admin's office, where he found the sysadmin and his assistant, staring at their terminal in frozen horror. Their screen had something like:
undefined

# rm -rf / tmp/*.log ^C^C^C^C^C^C^C^C^C^C # ls -l sh: ls: command not found # stat /bin/ls sh: stat: command not found
A few seconds after hitting return, and the rm command not finishing immediately, he realised about the errant space, and then madly hammered Ctrl-C to try to stop it. It turns out that the disk was slow enough that not everything was lost, and by careful use of the commands that hadn't been deleted, managed to copy the executables off another server without having to reinstall the OS.
- Oh no, that's horrifying.

I totally pulled a LTT and removed my kernel. >_< There was a "real time" kernel listed in apt, and I installed it because I was curious if it would reduce lock latency for a project I was working on. (I wasn't trying to solve a problem, just curious) It didn't and I figured it was probably a bad idea to leave it installed. So I did an apt remove, and the rest went something like this.
Apt: Are you sure you want to remove the your kernel? Y/N
Me: Oh jeez... I don't want to do that.
Motor Memory: Y
<return>

Apt: Are you really really sure? Your computer will not boot if you do this. Y/N
Me: Oh, crap! That's not what I meant to do. Definitely not!
Motor Memory: Y
<return>

Me: No! Why would my brain betray me!?
Fortunately this was on a PopOS machine, so I booted into the recovery partition. Even if fixing it only took a minute, I still felt very very dumb. >_<
- Man, that's a really dumb story that I find really relatable despite not having had any experiences like that. It feels like it'd be very in character for me though. Thanks for sharing, it helps me feel less silly in the various times where I've messed up (of which I am struggling to recall specific examples, but whatever brain part is responsible for embarrassment can remember, apparently)

The dumbest must have been when I went through the list of installed packages on Debian and removed everything named "python-..." since I don't program in python.
- This weirdly makes sense to me. Not long ago would have done the same.

I’m still stuck in vi
- :q
  
  Is that the “licking my own nose” emoticon?
  
  E37: No write since last change

Everyone here is talking about rm, but when’s the last time you dd’ed the wrong thing by accident?
You can get tripped up by tab completion, hda vs sda, sda vs sdb, flipping the articles around, he’ll, I’ve even blasted a good drive with /dev/random because I did t pay attention to what computer I’m logged into.
My killer app for multiple terminals open at once, weather through several ttys, xterms, tmux or the other one I don’t use was to type out my dd commands with a ls or something safe making in front of it while I look back and forth compulsively to verify that all the targets are correct.
- Only reason dd hasn’t bitten me is that in my head, if and of make perfect sense as input and output.
  Doesn’t mean I won’t make that error tomorrow, ofc. But I tend not to alias except harmless stuff to avoid that very problem.
- Yup, I did that last year. I wrote a Linux ISO to my hard drive instead of a flash drive. It was interesting watching my desktop slowly fail. Thankfully I was preparing a switch to a different distro, so I had backed up what I needed.
  
  All my drives are nvme* now.
  I feel so much safer punching in of=/dev/sdaX
- I haven't but I'm always terrified of doing it

Way back when I was just beginning to experiment with Linux back in the 90s I installed ZipSlack, which was a GUIless 100MB distro based on Slackware that ran from a folder on Windows. It was okay but I couldn't really do much with it and back then 100MB was a chunk of space, so i went to delete it. But i thought I would give it one last hurrah by deleting it from Linux. So I made use of the infamous rm -rf and sat there thinking "this is taking a long time"... then realised I had my Windows drive mounted as a sub folder and I was in the process of wiping my hard drive of everything!

I once removed all groups from my user by using usermod -g instead of usermod -G
- You probably mean that you used usermod -G instead of usermod -a -G
  The -a stands for append
  
  But you understand what I mean.
- I did the same! After that, I never tried to run that command from memory

I once tried to restore replication on a broken MySQL cluster by restoring the backup on the only good, running node.

Reformatted windows and installed Linux.
Wait before the hate. This was the first time I did it and knew nothing about it and didn't know it would wipe my system. So I lost everything.
- On the brighter side, you did delete windows.
  
  Yeah I don't see the problem here
- Sounds like a feature

How I lost a Postgres database:
Installed Postgres container without configuring a volume
Made a mental note that I need to configure a volume
After a few days of usage, restarted the container to configure the volume
...
Acceptance
- Well, that's a dumb Docker thing, not necessarily a dumb Linux mistake. You could've made the same mistake on Windows or MacOS when running Docker.
  
  Technically, containers always run in Linux. (Even on windows/OS X; on those platforms docker runs a lightweight Linux VM that then runs your containers.)
  And I wasn't even using Docker.

You know, I'm in a constant battle with bootloaders. I've both deleted grub multiple times and windows boot manager by accident and by believing "I could fix it by re-generating it"... More like re-installing.
- I've fixed the Windows bootloader before, but every result you find says something slightly different, feels like no one quite knows how to do it.
  https://forums.tomshardware.com/faq/how-to-repair-efi-bootloader-in-windows-10.3275168/
  
  Aren't we all on the same boat here? Thanks for the link btw! That's a new one I hadn't seen before.
- Virtualization...
  
  Yeah, yeah, I get the point. However, how else am I supposed to learn what not to do huh? "Do not delete your boot partition" is not obvious enough, I need consecuences for my stupidity.

Trusting tab-completion and pressing enter just a tiny bit too early, resulting in overwriting the work of at least four hours, because the files' names started the same. That whilst trying to initiate a git repository to prevent that kind of mistake....

"I have 200 GB of unused space in the windows partition, I'll just plug a live CD, divide that partition and merge it with the Linux one, ggez"
Yes, dividing the windows partition destroyed it. Yes, mixing the windows and ext destroyed Linux. I might have been able to recover something but I was like 18 and I just reinstalled windows in a fit of misdirected anger against Linux.
- Don't do that. Best option is to run windows in a VM. Second best option is to shrink windows in windows and the boot to a live system to grow linux
  
  No shit, now I daily drive Linux and I just have two separate drives for each, with some extra drives for games and files and such. That was 10-ish years ago.

dd if=/dev/zero of=/dev/sda status=progress
hmm why is it so fast
OH
CTRL-C
and then a kernel panic yeah my fs was gone

I do dumb things like edit my network configuration do some stuff and log out. Then I can't login the next weekend because the IP address is wrong. Also:
Ifconfig eth0 down
And I am booted from ssh.
- Yeah screwing with the network interface of the machine you're SSHd into is something nearly every sysadmin have done at least once.
  That or changing something, rebooting the server and subsequently being unable to contact it again due to said change. I'm always scared and feeling I'm taking a risk when upgrading a major OS version over SSH, yet Ubuntu never failed me in that, it's the silly things that got me, like messing with fstab.

I have a faint memory of once uninstalling python2 on an Ubuntu system trying to switch to python3. That was a fun learning moment.

Deleted the certs from the sshd daemon which locked me out of a remote server that required and a 2 hour drive to fix.
- Wonderful. Just like deleting all the iptables rules with a default DENY rule in place chef's kiss. Required calling the service provider to enable a remote console over HTTPS (it was a manual action for them... supposedly).
  Anti Commercial-AI license
  
  I'm curious: Is it a bad idea to have iptables with a default DENY rule? I use a deafult DENY in ufw, and it uses iptables under the hood.
- This is why we use ufw or firewalld. If nothing else setup an undo button

I installed timeshift to have a way to create restore points just in case I mess something up while fiddling with my Archbox.
I used it for a while before I decided to remove it. After that, I realized it didn't remove the "restore points" (I didn't fully understand how it worked) and thought it would be good idea to rm -rf /run/timeshift.
My whole /home was smited (it uses symlinks to create these "restore points"). Before I realized, it removed gigabytes of data.
Lesson learned: always understand how something works and always be careful when using rm -rf.
- Best advice when using rm -rf
  Don't.
- Nice.
  
  thanks

I distrohopped once and wanted to try OpenSuse Tumbleweed. Would have went really well if I didn't by accident deleted all my partitions...
I lost all of my curated music files I gathered over the span of the last 15 years.
I'll never get those back.
- Probably too late now lol, but you can totally recover deleted files if you don't overwrite them. I recommend the System Rescue image, it has a lot of tools to deal with these things.
- You know, you could have backups or better yet 3 copies on 2 mediums in 2 locations

Not me, and not Linux, but a school mate found the following bash snippet online :(){ :|:& };:.
Naturally, he tried it on the SunOS servers we had access to for schoolwork. He got his account suspended for the rest of the year.
I think most Linux distros are configured to kill fork bombs nowadays.

I accidentally overwrote /etc/passwd once and I allowed /boot to run out of space during a kernal update and I created a local user with the same user that was also on the realm/domain that I had joined and various bash script issues.
Some stuff I've had to fix that someone else did:
named a file rm -rf
rm -rf /bin instead of ./bin -- Also the fact that they had sudo was crazy and also I guess this was the second time
chmod -R 777 /
Various software bugs running swap out of space or hitting the inode limit by creating files over and over again with a timestamp in the filename and having to remove all of them because there was no backup to the OS
Someone disabled SELinux because something wasn't working but didn't tell anyone -- ugh
Compiled java because they googled some issue and followed some old tutorial without understanding anything instead of using alternatives and symlinked the old java from /bin to /home/theiruser/java -- had sudo because he was a Windows domain admin.
Cybersecurity guy didn't know what some VMs did so he turned them off and figured he'd find out if/when someone complained. Caused a massive core services outage.
Same Cybersecurity guy deleted a bunch of data because he wanted to see how the sysadmins would respond and witness backup restorations. He did not inform anyone.
Cybersecurity guy above still has Domain Admin and sudo everywhere. I would have personally removed his privileged access regardless of what 'CyberSecurity' management thought but I was leaving for a new job by then anyway so I figured I'd just let them eventually lie in the bed they made.
There's more but I don't want to keep going because it is Sunday and I don't want to ruin it.

Always do an echo first before you put rm in a script. You know the story.
- Alias rm to echo and install trash. Saved me many times.

Due to some poorly placed quotes, I managed to create a subdirectory named ~ in my home folder. You can imagine what happened next. Luckily, I had just gotten my backup system up and running the day before, so nothing was lost.

Trying to solve any Linux problem via ...

_Anti _{Commercial-AI} _license _(CC _BY-NC-SA _4.0)
- And then accidentally copy/pasting the failed attempt code snippets of the OP describing the situation.
  
  I've regularly found a solution to my problem on SO, only to discover that I need to figure out how to break my system exactly the same way the asker did before the fix will work.

My first experience with installing Linux on a hard drive involved wiping the wrong hard drive (my dad’s) and installing on it. Then panicking when Windows 95 didn’t boot up. Thank goodness my dad was understanding lol.

Wiping out Windows trying to install Linux seems to be a common thing. Did that while trying to install Ubuntu as a teen.
Funnily, I didn't check which Ubuntu iso I downloaded and ended up installing Ubuntu server. I should've noticed with the gui-less installer, but then I thought that it was just Linux being hightech.

I mounted a disk of a server in rescue mode, since I needed to extract everything (the provider didn't have the option to dump everything as a zip). Then installed an FTP server, added a user/pass, it worked.
But I couldn't access the files of the original disk, even though I could see them. So I just chgrp/chown the original files, since the disk was just "mounted" in the rescue disk /mnt, I thought it was alright (at the time I thought permissions were volatile, stored separately from the files). I could now download the entire disk, yay!
Upon booting the original disk again, a bunch of errors: shell not starting, tools not running, because they were owned by user and not root...
Well we reinstalled all the server from scratch that day.

Using sudo when it isn't necessary, and the real cannon: sudo su.. Adding sudo to your command lines indiscriminately causes files you create to be owned by root even though they are in your home directory, and then you end up using sudo to make changes to the files... and then the filesystem permissions cannot prevent you from successfully running an accidental "sudo rm -rf /" command.
Seriously... sudo is not a "habit" to develop in order to avoid dealing with filesystem permissions problems.
- this one used to fuck me up sooooo much.
- I regularly find myself trying to tweak some system config and opening the file read-only because I forgot to sudo vim it.
  Doesn't help that my everyday user account doesn't have sudo privileges, so I need to su to my admin account first.

Tip: don't put important things in just 1 place.
That aside!
Years ago when I first tried out Linux (I was around the age of 10), I didn't really pay much attention while installing Linux back then, so I wiped my entire data disk D:...
- I like the 3-2-1-1-0 backup rule personally.
  tl;dr:
  3 copies of your data
  on 2 different media
  at least 1 offsite copy
  1 copy offline (preferably air-gapped)
  0 errors (IE verified backups)
  (For the super important stuff, obviously. I'm more lax about other things.)

I updated a manjaro system.
- Did you... Kill-a-manjaro?
- I rebooted PC in the middle of Manjaro update. Apparently, kernel was updating, so it broke.
  Took me 15mins to restore, but they could make some safeguards.
  Other than that, never faced issues updating Manjaro.
  
  Well, there's a reason why Windows says "Don't turn off your computer" during updates. I think noob-friendly Linux distros should implement a similar system, where Kernel updates are only installed on shutdown and a message is displayed telling the user not to shut down their computer. There should still be rescue mechanisms like Btrfs snapshots or a recovery system that automatically detects a broken kernel and reinstalls it.
  
  I moved from Manjaro after a couple system updates just borked something like X11, but those happened over a 3 year course of using Manjaro.
  As insightful as it is to find the root cause of a Linux problem like that, on my main system it was just not something I wanted to deal with or risk having right when I need the PC.

i accidentally mark iwd as dependency rather than explicit. after that someday im removing a package depends on iwd, iwd itself been removed as a dependency as well. and im been blocked out of my remote machine until someday i have physical acces to it

The Arch installation tutorial I followed originally advised using LVM to have separate root and user logical volumes. However, after some time my root volume started getting full, so I figured I would take 10GB off of my home volume and add it to the root one. Simple, right?
It turns out that lvreduce --size 10G volgroup0/lv_home doesn't reduce the size by 10GB, it sets the absolute size to 10GB, and since I had way more than 10GB in that volume, it corrupted my entire system.
There was a warning message, but it seems my past years of Windows use still have me trained to reflexively ignore dire warnings, and so I did it anyway.
Since then I have learned enough to know that I really don't do anything with LVM, nor do I see much benefit to separate root/home partitions for desktop Linux use, so I reinstalled my system without LVM the next time around. This is, to date, the first and only time I have irreparably broken my Linux install.
- I was confused cause I remember reading this exact comment... I wondered if my brain is starting to fail and hallucinate...
  But no, you did post the same story 5 months ago :'D
  
  Oh no, I've been caught, haha. Good memory!
  To my defense, the story seemed relevant to OP's question, and the post that it was originally in has been deleted, apparently.

chmod'd all my home directory's files and folders recursively. First to 600, which prevented me from listing any folders, then to 700, which broke a few programs, then to 755, which broke ssh.
- Insert hammer meme

apt something that ended up removing sudo. No more admin rights.
used rsync to backup pretty much everything in / , with remove source option...
find with -delete option miss positioned. It deleted stuff before finding matching pattern
chown / chmod on /bin and/or /usr/bin
Removed everything in /etc
- On the first point: isn't it possible to just go su and reinstall sudo?
  Or does it not work with disabled root?
  
  It doesn't work with root disabled.
  The way to fix this is to boot in bash recovery where you land a root shell. From there you can hopefully apt install sudo if deb file is still in cache. If not, you have to make network function without systemd for apt install to work. Or, you can get sudo deb file and all missing dependencies from usb stick and apt install them from fs. Or just enable root, give it a password and reboot so you can su - and apt install sudo
- The first one can be fixed by using su
  
  Not if root account is disabled. Which is by default on Ubuntu and Debian . You'd need sudo su - but well... No sudo left you know.

Mine falls along with the people who were distracted. Was doing two deployments for work on night and on one I need to clear a cache. As I was typing the cd command, I happened to glance at the instructions for the other deployment and for some reason my mind switched to the deployment folder. I then typed out rm -rf *, and as I hit return realized I wasn't in the cache subdir. Blew away our prod environment and it took hours to get it all restored. The restore kept asking the guy to go pull tape #xxx. It was nerve wracking because depending on the tape, there was a chance it was moved offsite. Got it all restored and turned it back on, and then had to start back from the beginning since the backup was from the night before. The other people doing deployments weren't too happy, but I owned up immediately and we ended up changing the procedure. First, the cache clearing was done via a script after that, and I won my argument about not having to do two deployments simultaneously!

I was setting up fail2ban on an sftp server at work.
Guess who got admin permanently banned from that machine.
- I had a situation where I though my user was banned. I was troubleshooting an entirely different issue when it hit me. The Debian install was extremely corrupt. It was a restore from a snapshot but for some reason the snapshot was totally corrupted. I loaded a different snapshot and the machine worked fine.
  The .ssh/authorized_keys was just gibberish in the bad snapshot

Can't remember exactly what happened but it involved changing permissions on /bin /sbin and similar. You know for security ...
In the end I didn't have permissions to run chmod, su or sudo
Fortunately there is little that can't be fixed by booting from a live image.

My biggest thing when switching to Linux was understanding why I didn't have permission to alter half of my file structure. I was trying to take ownership of my /usr directory as a user and had to have multiple people explain why that was a bad idea (and why simply making any changes as a super user via terminal was more than adequate for the results I wanted).
My mindset was a result of so many user files being spread across dozens of branches of the Windows file structure. Some very close to the root of the drive, some a few directories deeper. I didn't really understand the benefit of having all my stuff in /home (and am now a full convert. Just thinking about navigating a Windows drive makes my skin crawl now).
- That's one damn fine username you got there!!
  
  Gotta say, yours ain't bad either my friend

Not me but a colleague of mine wrote a bash script that had something like this and ran it on a server:
undefined

FOO="/home/bar" ... Many lines later ... rm -rf $FOOT/*
Reminder that bash will resolve uninitiated variables to the empty string.
Luckily he halted the process after it had only nuked /boot and /bin. If it had gotten to /var and the mounted data storage within, we would have been in trouble
- Do you work at Valve?
- Always use set -eu
  
  Yeah if you don't put bash in European mode, it is a lot more dangerous.
- Ahhhh why not anything in /tmp or better ${TMPDIR:-/tmp} or best mktemp

For this very reason, I have aliased rm -rf with trash-cli
- Its fine as long as you are very careful. Best option is to just not delete anything. mv is your friend.
  It also helps to have a VM with snapshots

My buddy was in a class doing a programming test. It was a couple minutes until turn in time, so he went to zip up the source files. He had already ran the appropriate zip command previously, so he pressed up three times and then enter. It appears he had miscalculated, because the command that ran was rm *.c. There were no backups.
- Linux commands are brutal

I once just uninstalled sudo and replaced it with doas. Turns out, the shutdown process needs sudo and a lot more. So I am still using my system since then, without shutting down.
No joking, I use Fedora Atomic and can not break my system... unless you mess up your dotfiles, and a lot more.
I also put a drive into my /etc/fstab once without the nofail argument.
No idea why that is not set by default, but when removing that drive my system couldnt boot and I exited to a very scary dracut shell.
- Wait .. you can uninstall sudo?
  
  Wait till you find out that you can even uninstall Linux!
  
  On "immutable" Fedora, yes :D dont know if I needed to add some enforcement variable.
- Legend has it he still hasn't shut down to this day...

I just finished doing a fresh install this morning, because my wifi card wasn't working. It honestly needed to be done anyway because I was out-of date, but the wifi card finally got me to back-up all my data and do it.
Fresh install, and wifi still won't even toggle-on. Was about to look for manual install of the driver, and so on and so forth... and then I noticed my folly
Fucking keyboard has a toggle switch to turn the wifi off. Not the worst and glad I didn't pull my hair out over it, but damn... felt pretty dumb this morning

$ grub-mkconfig -o /boot/grub/grub.conf
Thaaat... took me a stupid amount of time to fix.
- There's nothing wrong with that command, per se. You must've ducked up something else?
  
  It's grub.cfg not grub.conf. it's really easy to miss because everything else is .conf.

301 comments