Linux

48248 readers

804 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]

Systemd 254 - now with soft-reboot (github.com)

submitted 1 year ago by [email protected] to c/[email protected]

14 comments fedilink hide all child comments

Systemd 254 released and now has a new soft-reboot option:

    * A new "soft-reboot" mechanism has been added to the service manager.
      A "soft reboot" is similar to a regular reboot, except that it
      affects userspace only: the service manager shuts down any running
      services and other units, then optionally switches into a new root
      file system (mounted to /run/nextroot/), and then passes control to a
      systemd instance in the new file system which then starts the system
      up again. The kernel is not rebooted and neither is the hardware,
      firmware or boot loader. This provides a fast, lightweight mechanism
      to quickly reset or update userspace, without the latency that a full
      system reset involves. Moreover, open file descriptors may be passed
      across the soft reboot into the new system where they will be passed
      back to the originating services. This allows pinning resources
      across the reboot, thus minimizing grey-out time further. This new
      reboot mechanism is accessible via the new "systemctl soft-reboot"
      command.>

all 19 comments

sorted by: hot top controversial new old

[–] [email protected] 3 points 1 year ago

If I'm understanding this right it seems like a good fast way to test that services start up properly without doing a full reboot so that's pretty nice.

[–] [email protected] 1 points 1 year ago* (last edited 1 year ago)

Hard-reboots are no longer required on Silverblue when installing or upgrading packages (besides kernel) through rpm-ostree. Arguably one should only sparingly rely on rpm-ostree for installing packages. But it's great to have access to soft-reboot when setting up a new system.

[–] [email protected] 1 points 1 year ago

Also:

When the system hibernates, information about the device and offset used is now written to a non-volatile EFI variable. On next boot the system will attempt to resume from the location indicated in this EFI variable. This should make hibernation a lot more robust, while requiring no manual configuration of the resume location.

[–] [email protected] 1 points 1 year ago (1 children)

Support for System V service scripts is now deprecated and will be removed in a future release. Please make sure to update your software now to include a native systemd unit file instead of a legacy System V script to retain compatibility with future systemd releases.

Why is this being removed?

I wouldn't use it but it certainly seems handy for a quick hack and also for people who are used to the old ways.

[–] [email protected] 1 points 1 year ago (1 children)

Maintaining legacy options is always maintenance overhead or things you need to work around when implementing new features. I suspect that they've concluded that not enough people use it anymore to justify the overhead.

[–] [email protected] 1 points 1 year ago* (last edited 1 year ago)

Yeah it’s not like service files are difficult to write. They’re certainly easier than sysv init files

[–] [email protected] 0 points 1 year ago (1 children)

So is this like that windows 'fast boot' or whatever it's called thing?

[–] [email protected] 1 points 1 year ago (1 children)

It is nothing like that. Windows fast boot is just fancy resume from hibernation.

[–] [email protected] 1 points 1 year ago

It's a mix. It hibernates what would be the result of a systemd soft-reboot, before user space starts up again.

[–] [email protected] 0 points 1 year ago* (last edited 1 year ago) (1 children)

Does that mean we will be able to update graphics drivers without a full reboot if the kernel didn't update?

[–] [email protected] 1 points 1 year ago

I don't think any graphics drivers run in user-space, so probably not.