Re: sysctl to prevent reboot?

From: Warner Losh <imp_at_bsdimp.com>
Date: Thu, 10 Jul 2025 14:32:51 UTC 
On Thu, Jul 10, 2025, 8:30 AM Konstantin Belousov <kostikbel@gmail.com>
wrote:

> On Thu, Jul 10, 2025 at 01:51:47PM +0000, Bjoern A. Zeeb wrote:
> > On Thu, 10 Jul 2025, Zhenlei Huang wrote:
> >
> > Hi,
> >
> > > I believe Konstantin's work [1] and  [2] are precisely what you need.
> > >
> > > [1]
> https://cgit.freebsd.org/src/commit/?id=7fb88c20eccc3fd2118fda2ba58d7afe2b87f7e3
> <
> https://cgit.freebsd.org/src/commit/?id=7fb88c20eccc3fd2118fda2ba58d7afe2b87f7e3>
>  shutdown(8): refuse to run if /var/run/noshutdown is present
> > > [2]
> https://cgit.freebsd.org/src/commit/?id=384d976725a5c29734a9227fcdb6ef0807485c91
> <
> https://cgit.freebsd.org/src/commit/?id=384d976725a5c29734a9227fcdb6ef0807485c91>
> rc.d: Add precious_machine rc.conf knob to create /var/run/noshutdown
> >
> > Thanks!  I was looking in the wrong place.
> >
> > That doesn't catch reboot, does it?  For me that's the offending command
> > as I type that at the loader prompt (if I am in the correct window).
>
> Reboot is very different from shutdown.  I never use it except on
> nfs-booted
> crash boxes, so I did not considered.
>
> If you think it is useful, I can add the check there too.
>

There have been other proposals that align reboot better with Linux's
behavior, then a special check isn't needed.

Warner

>