On Mon, Nov 02, 2015 at 01:34:57PM -0500, Jon Stanley wrote:
On Mon, Nov 2, 2015 at 1:29 PM, Jon Stanley
<jonstanley(a)gmail.com> wrote:
> Other than that looks great!
Oops, one more - KillMode=process is important for sshd, but probably
not for 99.9% of other units, so it was probably a bad choice to
examine. What it really does is when you stop it, systemd only
terminates the main PID, and not any children that may be in the same
cgroup. For sshd, this is critical since if you are connecting via
ssh, and do 'systemctl stop sshd.service', then your session would die
since it would kill everything in the cgroup.
I'm not certain if we want to get into details like that in this post
(it's somewhat esoteric), but it is critically important IMO to
understanding how systemd uses cgroups to group processes and
optionally apply resource controls to them.
We haven't gone deeply into cgroups and I was thinking of saving that
for an additional post. But this is probably something that can be
explained in simple terms in the article, as you've explained it quite
well here. The fact that it's an abnormal usage is not necessarily a
terrible choice.
--
Paul W. Frields
http://paul.frields.org/
gpg fingerprint: 3DA6 A0AC 6D58 FEC4 0233 5906 ACDB C937 BD11 3717
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