Re: [CentOS-devel] Balancing the needs around the RHEL platform

On Fri, Jan 01, 2021 at 04:50:44PM -0500, Nico Kadel-Garcia wrote:

possible to set the boot loader to consider one kernel as the "default", but to beet the next time with a designated kernel one time only. It made testing kernels safer because a failed kernel installation failed reboot only *once* and only needed a power cycle to revert. I don't believe grub has ever been successfully patched to support this: I'd welcome it if they did, though i'm not testing hardware and kernels these days.

Grub can do a number of fancy things, including "boot once" and (I think probably better) a "fallback" option. (You may want `kernel.panic = 10` or something in /etc/sysctl.conf to go along with this, depending on what kind of failure you're expecting.)