Fedora 23 自訂核心開機順序
Step1)列出目前開機預設選項
#grub2-editenv list
Step2)從/boot/grub2/grub.cfg找出開機選項，以menuentry為開頭找出選項
#grep ^menuentry /boot/grub2/grub.cfg
螢幕輸出結果
menuentry 'Fedora (4.2.3-300.fc23.i686+PAE) 23 (Twenty Three)' --class fedora --class gnu-linux --class gnu --class os --unrestricted $menuentry_id_option 'gnulinux-4.2.3-300.fc23.i686+PAE-advanced-9c8c591f-7074-4c86-b407-4fe382a7d7e3' {
menuentry 'Fedora (4.2.3-300.fc23.i686) 23 (Twenty Three)' --class fedora --class gnu-linux --class gnu --class os --unrestricted $menuentry_id_option 'gnulinux-4.2.3-300.fc23.i686-advanced-9c8c591f-7074-4c86-b407-4fe382a7d7e3' {
menuentry 'Fedora (0-rescue-1ededfabf8a54aca97896d9ce810e209) 23 (Twenty Three)' --class fedora --class gnu-linux --class gnu --class os --unrestricted $menuentry_id_option 'gnulinux-0-rescue-1ededfabf8a54aca97896d9ce810e209-advanced-9c8c591f-7074-4c86-b407-4fe382a7d7e3' {
Step3)設定預設的核心
#grub2-set-default "Fedora (4.2.3-300.fc23.i686) 23 (Twenty Three)"