20.19. kb-00018: Can I eliminate reboots with kexec?

20.19.1. Knowledge Base Article: kb-00018

20.19.2. Description

Installing operating systems often times requires a reboot of the Machine several times. For physical (aka bare) metal, this reboot cycle can add many minutes (often times 10 or more minutes) to the installation process.

When installing Linux operating systems, it may be possible to utilize the Linux Kernel kexec mechanism to “exec” in to the new Kernel environment without requiring the Machine to pass through a full POST cycle.

20.19.3. Solution

Setting the kexec-ok param to true on the global or machine specific profile allows BootEnvs that are kexec enabled to skip rebooting when changing to that BootEnv. For example, Sledgehammer enables kexec and can be started without a reboot from Linux environments.

This is a Linux specific feature.

Note

The kexec capability is defined by the compiled Linux Kernel configuration. Some Linux distributions do not enable kexec by default. In these cases, you may have to compile a custom kernel version with kexec enabled. In addition, not all transition states can successfully utilize kexec even if it is enabled in the kernel.

20.19.4. Additional Information

Additional resources and information related to this Knowledge Base article.

20.19.4.2. Versions

Enabled in the v3.x versions and newer.

20.19.4.3. Keywords

sledgehammer, kexec, post, reboot

20.19.4.4. Revision Information

KB Article     :  kb-00018
initial release:  Wed Jun 10 11:40:54 PDT 2020
updated release:  Wed Jun 10 11:40:54 PDT 2020