Systemd Starts Killing Your Background Processes By Default (blog.fefe.de)

New submitter nautsch writes: systemd changed a default value in logind.conf to "yes", which will kill all your processes, when you log out... There is already a bug-report over at debian: Debian bug tracker.
The new change means "user sessions will be properly cleaned up after," according to the changelog, "but additional steps are necessary to allow intentionally long-running processes to survive logout. To effectively allow users to run long-term tasks even if they are logged out, lingering must be enabled for them."

Comments

Re:security best practice?

[Anonymous Coward]

you should explicitly state so

nohup

Re:security best practice?

[jsm300]

How about doing anything that takes a long time and you don't want to remain logged in for it to complete? For example you are running a standard program that is going to take hours or even days to process some data, so you redirect stdin to /dev/null, stdout to one file, stderr to either the same file or another file, and you start the whole thing with the nohup shell command.

There is already a well established mechanism for cleaning up background processes, i.e. the SIGHUP signal. And there is already a mechanism for explicitly stating that you don't want a process to die when you log out, and that is the shell's "nohup" command (which blocks the hangup signal that is sent to the process when the user exits).

And in what way does this new mechanism "enhance security"? Running something in the background after you log out doesn't give you any more privileges than if you remained logged in.

Why do the systemd folks think they need to keep reinventing the wheel? This feels like a solution in search of a problem.

Re:WTF

[Etcetera]

FWIW, I've only found one quote by Lennart Poettering about the entire thing (source):

I am not sure I follow. Note that user@.service is already reference counted by the login sessions around. i.e. it is started before the first user session of a specific user is created, and stopped when the last user session ends. I don't follow why that behaviour is not sufficient?

Lennart seems to have learned by now to be careful what he says in public, so I don't expect him to call anyone a moron here.

No, there's a similar debate blowing up on the Fedora list as well, it's just that there's hardly anyone left with the energy to fight the cabal any more.

From the Fedora List:

In my view it was actually quite strange of UNIX that it by default let arbitrary user code stay around unrestricted after logout. It has been discussed for ages now among many OS people, that this should possible but certainly not be the default, but nobody dared so far to flip the switch to turn it from a default to an option. Not cleaning up user sessions after logout is not only ugly and somewhat hackish but also a security problem.

...

I am pretty sure we should consider it our duty as Fedora developers to improve the Linux platform, and I am pretty sure that properly cleaning up processes on logout is a step towards that, not against it.