Linux

48328 readers

100 users here now

From Wikipedia, the free encyclopedia

Linux is a family of open source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991 by Linus Torvalds. Linux is typically packaged in a Linux distribution (or distro for short).

Distributions include the Linux kernel and supporting system software and libraries, many of which are provided by the GNU Project. Many Linux distributions use the word "Linux" in their name, but the Free Software Foundation uses the name GNU/Linux to emphasize the importance of GNU software, causing some controversy.

Rules

Posts must be relevant to operating systems running the Linux kernel. GNU/Linux or otherwise.
No misinformation
No NSFW content
No hate speech, bigotry, etc

Related Communities

Community icon by Alpár-Etele Méder, licensed under CC BY 3.0

founded 5 years ago

MODERATORS

[email protected]

Can someone explain this command for me? (lemmy.ml)

submitted 2 months ago by [email protected] to c/[email protected]

9 comments fedilink hide all child comments

Today I just learned that systemctl --force --force reboot is a command. We had a computer we remotely connected to which got permission errors and bus errors when we tried to reboot it normally. For some reason the mentioned command did actually manage to shutdown the computer bit did not manage to reboot it correctly.

I wonder what the double --force flag actually accomplishes and what possibly could hinder a regular reboot in this scenario.

all 12 comments

sorted by: hot top controversial new old

[–] hitwright 90 points 2 months ago (2 children)

As per systemctl(1) manual:

If --force is specified twice, the operation is immediately executed without terminating any processes or unmounting any file systems. This may result in data loss. Note that when --force is specified twice the halt operation is executed by systemctl itself, and the system manager is not contacted. This means the command should succeed even when the system manager has crashed.

[–] [email protected] 31 points 2 months ago (1 children)

Ah, the --no-preserve-root flag equivalent for a reboot 😄

[–] [email protected] 2 points 2 months ago

Good old --no-preserve-root 😅

[–] [email protected] 9 points 2 months ago

Sounds like the equivalent of Alt+SysRq+B.

[–] t0m5k1 22 points 2 months ago (3 children)

I'd never use it on a production server due to the implications of data loss associated with such a command.

You could say this is the same as sysreq trigger b where everything is ignored and just reboot with ignorance.

[–] [email protected] 2 points 2 months ago

You can force the kernel to terminate all processes and amount all filesystems

[–] [email protected] 1 points 2 months ago (1 children)

This is very valid but in our case we dont really store any important data on the computer. We make digital timetable signs for bus stops and train stations, the computers we build and put inside are just a base image we flash onto the disk and set hostname and IP on. Then they all connect and set themselves up via our servers and pull any displayed data from our actual main servers.

In this case its sad that it didnt actually restart, that means our client has to drive out and deassemble the entire sign. But it seems to be a failing disk so it had to be replaced either way.

[–] [email protected] 2 points 2 months ago

As long as it's not writing to disks, you're probably safe. This is a good method to avoid getting a remote device stuck too.