Dear Unix diary,

Today I discovered a neat trick involving /proc
Some user complained AGAIN that their development server was full. Indeed, they have a component whose logs are set in "DEBUG" mode, which makes it fill the available space rather quickly (and they don't want to do anything about it, because they're lazy asses!).
So as usual, I log onto the machine, perform the traditionnal "df -h" semi-automatically, and then navigate to the log directory that I know is guilty. But this time, I was surprised:


Ah, so there might be another guilty app! which one is it?


WTF? Then I got enlightenned... Someone deleted a huge ass file, while it was still openned!
Dammit, I already told them not to play heroes on the box, and call me instead...
After some research and the help of our good IRC members (props to SOMEONE[1] for finding the link).

This stackoverflow post advise to use "lsof" to find the openned. I already though about it, but lsof was not installed on the box, and the disk being full didn't allow me to install it. So I had to go with another option.
Hopefully, another answer on the page suggested an alternative, which I tried immediately:


I found them! I told them that restarting their component would free the space, but being too busy "coding", they couldn't afford a reboot. So I just temporarily emptied the file descriptors by hand ("> /proc/3568/fd/1" , and let them go with it.
/proc/3568/fd/1

Hooray! Unix will always impress me!

[1] ymbx doesn't deserves the honor of being cited. Die alone man.