Soft Reboot⌗

Talk by Luca Boccassi.

This talk is about a new systemd feature. Soft reboot. Targeted towards performance, service interruption. Service downtime should be minimized.

This should pair nicely with kernel ’live patching'.

For the kernel ’nothing at all is happening’. However, for userspace it is a full shutdown/reboot.

With a File Descriptor Store applications can buffer connections to keep them alive while the system goes for a soft-reboot.

The soft-reboot allows containers to keep running. However, they need to be disconnected from the rootfs.

Demo shows an executable (‘sleep infinity’) in a Podman container. The system goes for a soft-reboot, restarts all the services. And afterwards the executable is shown to still be running, with the same pid it had before.

Conclusion⌗

Interesting feature. Judging from the demo it seems to work well. What I mainly wonder after this talk, is still the same thing I had before this talk, how often do you want to reboot your system this way. Often the reason for me to reboot is updating the kernel. Services and applications can be restarted on their own.

References⌗

Soft Reboot: keep your containers running while your image-based Linux host gets updated