document systemctl soft-reboot

## Remaining nodes

The [Nagios unhandled problems](https://nagios.torproject.org/cgi-bin/icinga/status.cgi?allunhandledproblems) will show remaining hosts that

might have been missed by the above procedure..

might have been missed by the above procedure.

## Userland reboots

systemd 254 (Debian 13 trixie and above) has a special command:

    systemctl soft-reboot

That will "shut down and reboot userspace". As the [manual page

explains](https://manpages.debian.org/testing/systemd/systemd-soft-reboot.service.8.en.html):

> systemd-soft-reboot.service is a system service that is pulled in by

> soft-reboot.target and is responsible for performing a

> userspace-only reboot operation. When invoked, it will send the

> SIGTERM signal to any processes left running (but does not follow up

> with SIGKILL, and does not wait for the processes to exit). If the

> /run/nextroot/ directory exists (which may be a regular directory, a

> directory mount point or a symlink to either) then it will switch

> the file system root to it. It then reexecutes the service manager

> off the (possibly now new) root file system, which will enqueue a

> new boot transaction as in a normal reboot.

This can therefore be used to fix conditions where systemd itself

needs to be restarted, or a lot of processes need to, but not the

kernel.

This has not been tested, but could speed up some restart conditions.