replace the content of /etc/default/grub.d/kexec-tools.cfg with:
KEXEC_TOAPPEND="crashkernel=384M-:128M"
case "$GRUB_CMDLINE_LINUX_DEFAULT" in *$KEXEC_TOAPPEND*) ;; *) GRUB_CMDLINE_LINUX_DEFAULT="$GRUB_CMDLINE_LINUX_DEFAULT $KEXEC_TOAPPEND" ;; esac
replace the content of /etc/default/ grub.d/ kexec-tools. cfg with:
KEXEC_TOAPPEND= "crashkernel= 384M-:128M"
case "$GRUB_ CMDLINE_ LINUX_DEFAULT" in TOAPPEND* )
GRUB_CMDLINE_ LINUX_DEFAULT= "$GRUB_ CMDLINE_ LINUX_DEFAULT $KEXEC_TOAPPEND"
*$KEXEC_
;;
*)
;;
esac