Alternate rescue boot entry with systemd

Thu, 23 Oct 2014 20:06:30 -0000
debian, eng, pdo, sw, truelite, systemd

Since systemd version 215, adding systemd.debug-shell to the kernel command line activates the debug shell on tty9 alongside the normal boot. I like the idea of that, and I'd like to have it in my standard 'rescue' entry in my grub menu.

Unfortunately, by default update-grub does not allow to customize the rescue menu entry options. I have just filed #766530 hoping for that to change.

After testing the patch I proposed for /etc/grub.d/10_linux, I now have this in my /etc/default/grub, with some satisfaction:

GRUB_CMDLINE_LINUX_RECOVERY="systemd.log_target=kmsg systemd.log_level=debug systemd.debug-shell"

Further information:

man systemd-debug-generator

the Debian wiki page on systemd

Thanks to sjoerd and uau on #debian-systemd for their help.