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Comment by JBiserkov | Hacker News Reader

>The command to reboot the select set of new systems that needed to be updated was mis-typed, and instead specified all servers in the datacenter.

Substitute reboot with 'upgrade to win 7' and data center with university at get a story from a month? ago.

     rm ./*.* - delete all files in current dir

     rm /*.* - never do this

Can you spot the difference? A colleague did the later on our testing server. No clients were disturbed, but us devs were left working on things that can run locally (much more pleasant stuff for sure, yet the schedule suffered a lot).

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I once went to shutdown our staging realm to do some task.

    ~/realm_control_production$ ./realmctl.py stop --no-warn

Oh shit, that is production, not staging. I got the surge of adrenaline and hit Ctrl+C within a couple of seconds.

Thankfully it only completed the very first part of the process that prevents new users from logging in and puts up the maintenance page. No playing users were kicked off the game servers. All I had to do was run

    ./realmctl.py allow

to get new logins to start working again.

This is what taught us that we need to have an extra confirmation for actions on the production realm.

That is why my production terminal windows are red background with yellow text, because I sometimes "space out" the prompt.

This is good advice. I have always followed that through by insisting $PS1 has a bright red banner that says "PRODUCTION".

I like that one, I will have to try that out. A damn shame you cannot add animation to the prompt.

So, it's now like this?

    ~/realm_control_production$ ./realmctl.py stop --no-warn --no-really --i-know-its-production

Your 'never do this' line would erase initrd.img on most machines, which you'd only find out about after the next reboot if nobody told you about it (and good luck getting that fixed).

There are a large number of varieties of this particular error. Some with terrible results.

rm -rf * .bak

for instance (especially when executed in the root directory).

That '#' prompt is there for a reason.

The way to solve these sort of issues is to first get the files using 'find' until you're totally happy about the result and then to use 'rm' as the command passed to find.

Of course, nobody does this ;)

>Your 'never do this' line

Would also erase everything else on the box so you might not know for a few seconds, but then the database errors start and the lib and pid files start disappearing and now your the king of a mountain of shit. It won't take till next reboot to notice.

If you ever get a chance, rm -rf / a box before you throw it out and just play around with it for a couple minutes while it eats itself.

You can spare your self most errors like that with tab complete, the built in sanity checker. I tab complete everything since I'm dyslexic, and it saves me a shit ton of time cause I'm never far from the error when I notice it.

> Would also erase everything else on the box so you might not know for a few seconds, but then the database errors start and the lib and pid files start disappearing and now your the king of a mountain of shit. It won't take till next reboot to notice.

Yes, it will, because the original post didn't include -r. So it's only deleting things that match the glob in the root directory. On many systems, that is nothing.

Even with -r,

  /*.*

only matches files and directories in / that have a period in their name. So it would skip over /usr, /home, etc.

That's what "match the glob" means.

My point was that the lack of -r doesn't really change anything; even with -r, it would still only delete initrd.img and similar, which would take until the next reboot to notice.

You have the same fun in an emulator (even http://bellard.org/jslinux/ is somewhat good enough).

Another one with a space is from the bumblebee install script where it removed /usr

Instead of /usr/some/path/here

http://www.miltonbayer.com/blog/news/when-a-code-commit-goes...

>rm -rf * .bak

Try

  chown -R user:group /var/local/some/data/dir /

inside an init script. Of course it had been tested many times, and the space was only fat-fingered in when someone move the data directory.

Ah yes. There are so many ways to bork a box.

A colleague of mine once called me over because they were having trouble with their computer. Apparently while doing "a little tidying up" they decided to move the windows folder to somewhere else. I can't remember the details but for some reason it was impossible to get a command prompt (Windows NT maybe?) without a disk, which I didn't have. I think I had to rip the drive out and stick it in another machine to fix it.

You know what's also fun. Try deleting all files that start with a . in your current directory:

    rm -rf .*

Would you expect this to go UPWARD? I would have never. I.e. even if you're in /x/y/z it will traverse up the tree and start deleting /x and eventually /.

'..' starts with '.', but I wouldn't have expected it to go more than one level up. I guess it saw ../.., then ../../.. ...

These days, any time I do an rm with a wildcard, I always prepend with a directory, no matter how trivial, just to keep in the habit. 'rm ../mydir/.*'

The incident was at Emory University: http://thenextweb.com/shareables/2014/05/16/emory-university...

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