Kexec instead of reboot?

This is more a feature request than a question, but is RancherOS planning on supporting Kexec reboots like CoreOS?

On a bare metal server with hardware RAID, PXE boot for booting into rescue/reinstall mode and the ordinary BIOS is a tediously lengthy process, while after an upgrade you’d want the server back up and running ASAP. By directly booting into a (new) kernel all the BIOS/hardware/boodloaders are skipped, drastically reducing downtime.


Thumb up! This should be nice feature to introduce.

Kexec will be included in v0.4.4 and ros os upgrade will have a flag to make use of it to reboot.


Did this ever happen @joshwget? I can’t find kexec in v0.5.0, hopefully I’m not looking hard enough.

Check out the --kexec flag for ros os upgrade. kexec is actually packaged in the upgrade image, which is why you haven’t been able to find it in our base image. It might make sense to have it available in the base image as well though.

Nice one @joshwget, thank you.

It would be helpful in my scenario to have it in the base image but frankly, only because our blade’s boot time is ridiculously long and I’m rebooting often only to test various things. In normal operations, the upgrade option is enough.