4 ms·

Not sure about their reasoning.. but if you don't have root ssh enabled, sudo can break if there is no free disk space. I do something similar where I write a 5

Not sure about their reasoning.. but if you don't have root ssh enabled, sudo can break if there is no free disk space. I do something similar where I write a 500mb file to /tmp and chmod 777 it so anyone can free it up without needing sudo.

franga2000 6y ago
I've experienced far more full disks than I'd want to admit, on many different hardware and software configurations, and I've never seen sudo break. Is this something you've experienced recently? I definitely agree with your advice and will go double check all my servers if /filler is 777 (not in /tmp since it's sometimes mounted tmpfs), but if sudo does break in that situation, that sounds like a pretty severe and most likely fixable bug.
- bostonsre 6y ago
  Yea, have seen it recently on centos 7. I think it's due to having sudo logging enabled. It won't let you run sudo without it working (at least I think that's the case, but haven't spent the time to investigate too thoroughly).
jeroenhd 6y ago
I've never had sudo break on my full disks. However, that doesn't mean recovery is easy... Working in a terminal to find out what on earth has just filled up your disk is a real pain when your shell complains about failing to write to your $HISTFILE and such. And, of course, the problem always shows up on that one server that doesn't have ncdu installed... I'm sure sudo can theoretically break with 0 free disk space, but that's not the usual mode of failure in my experience. At most sudo need to touch a dotfile or two, so deleting _any_ temporary file or old log archive will do for it to recover. The balloon file is not a bad idea. I think I will apply it on my own servers just for good measure, although 8GiB is a bit much for my tastes.
reph2097 6y ago
In that case, use "su".
- bostonsre 6y ago
  No luck when I've tried that. I think it's tied to sudo logging not working when the disk is full.

franga2000 6y ago

I've experienced far more full disks than I'd want to admit, on many different hardware and software configurations, and I've never seen sudo break. Is this something you've experienced recently? I definitely agree with your advice and will go double check all my servers if /filler is 777 (not in /tmp since it's sometimes mounted tmpfs), but if sudo does break in that situation, that sounds like a pretty severe and most likely fixable bug.

bostonsre 6y ago
Yea, have seen it recently on centos 7. I think it's due to having sudo logging enabled. It won't let you run sudo without it working (at least I think that's the case, but haven't spent the time to investigate too thoroughly).

jeroenhd 6y ago

I've never had sudo break on my full disks. However, that doesn't mean recovery is easy... Working in a terminal to find out what on earth has just filled up your disk is a real pain when your shell complains about failing to write to your $HISTFILE and such. And, of course, the problem always shows up on that one server that doesn't have ncdu installed... I'm sure sudo can theoretically break with 0 free disk space, but that's not the usual mode of failure in my experience. At most sudo need to touch a dotfile or two, so deleting _any_ temporary file or old log archive will do for it to recover. The balloon file is not a bad idea. I think I will apply it on my own servers just for good measure, although 8GiB is a bit much for my tastes.

reph2097 6y ago

In that case, use "su".

bostonsre 6y ago
No luck when I've tried that. I think it's tied to sudo logging not working when the disk is full.