ubuntu更改启动顺序
在ubuntu中修改启动配置。
启动相关grub2主要包含下面三个文件：1. /boot/grub/grub.cfg 文件 2. /etc/grub.d/ 文件夹 3. /etc/default/grub 文件，可以通过修改这三个文件来修改启动项
链接：http://blog.csdn.net/zhu_liangwei/article/details/7847034
一
更改启动顺序，验证过的两种方式
1、修改 /etc/default/grub 文件
打开文件
sudo gedit /etc/default/grub
修改文件
GRUB_DEFAULT=0 #更改数字设置默认启动项
更新
sudo update-grub
1 # If you change this file, run 'update-grub' afterwards to update 2 # /boot/grub/grub.cfg. 3 # For full documentation of the options in this file, see: 4 # info -f grub -n 'Simple configuration' 5 6 GRUB_DEFAULT=7 #更改数字设置默认启动项 7 #GRUB_HIDDEN_TIMEOUT=0 8 GRUB_HIDDEN_TIMEOUT_QUIET=true 9 GRUB_TIMEOUT=10 10 GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian` 11 GRUB_CMDLINE_LINUX_DEFAULT="quiet splash" 12 GRUB_CMDLINE_LINUX="" 13 14 # Uncomment to enable BadRAM filtering, modify to suit your needs 15 # This works with Linux (no patch required) and with any kernel that obtains 16 # the memory map information from GRUB (GNU Mach, kernel of FreeBSD ...) 17 #GRUB_BADRAM="0x01234567,0xfefefefe,0x89abcdef,0xefefefef" 18 19 # Uncomment to disable graphical terminal (grub-pc only) 20 #GRUB_TERMINAL=console 21 22 # The resolution used on graphical terminal 23 # note that you can use only modes which your graphic card supports via VBE 24 # you can see them in real GRUB with the command `vbeinfo' 25 #GRUB_GFXMODE=640x480 26 27 # Uncomment if you don't want GRUB to pass "root=UUID=xxx" parameter to Linux 28 #GRUB_DISABLE_LINUX_UUID=true 29 30 # Uncomment to disable generation of recovery mode menu entries 31 #GRUB_DISABLE_RECOVERY="true" 32 33 # Uncomment to get a beep at grub start 34 #GRUB_INIT_TUNE="480 440 1"
配置文件详解 http://lesca.me/archives/manage-grub2-config-file.html
二
修改 /boot/grub/grub.cfg文件，使用sudo update-grub会被覆盖掉。
打开文件
sudo gedit /boot/grub/grub.cfg
修改文件
set default = '0' 修改数字
1 # 2 # DO NOT EDIT THIS FILE 3 # 4 # It is automatically generated by grub-mkconfig using templates 5 # from /etc/grub.d and settings from /etc/default/grub 6 # 7 8 ### BEGIN /etc/grub.d/00_header ### 9 if [ -s $prefix/grubenv ]; then 10 set have_grubenv=true 11 load_env 12 fi 13 set default="7" #改这个数字设置默认启动项，启动项的特征在下面有标记 14 if [ "${prev_saved_entry}" ]; then 15 set saved_entry="${prev_saved_entry}" 16 save_env saved_entry 17 set prev_saved_entry= 18 save_env prev_saved_entry 19 set boot_once=true 20 fi 21 22 function savedefault { 23 if [ -z "${boot_once}" ]; then 24 saved_entry="${chosen}" 25 save_env saved_entry 26 fi 27 } 28 29 function recordfail { 30 set recordfail=1 31 if [ -n "${have_grubenv}" ]; then if [ -z "${boot_once}" ]; then save_env recordfail; fi; fi 32 } 33 34 function load_video { 35 insmod vbe 36 insmod vga 37 insmod video_bochs 38 insmod video_cirrus 39 } 40 41 insmod part_msdos 42 insmod ext2 43 set root='(hd0,msdos7)' 44 search --no-floppy --fs-uuid --set=root dea69c19-08d2-433a-89b9-f917b6d5cce4 45 if loadfont /usr/share/grub/unicode.pf2 ; then 46 set gfxmode=auto 47 load_video 48 insmod gfxterm 49 insmod part_msdos 50 insmod ext2 51 set root='(hd0,msdos7)' 52 search --no-floppy --fs-uuid --set=root dea69c19-08d2-433a-89b9-f917b6d5cce4 53 set locale_dir=($root)/boot/grub/locale 54 set lang=zh_CN 55 insmod gettext 56 fi 57 terminal_output gfxterm 58 if [ "${recordfail}" = 1 ] ; then 59 set timeout=30 60 else 61 set timeout=10 62 fi 63 ### END /etc/grub.d/00_header ### 64 65 ### BEGIN /etc/grub.d/05_debian_theme ### 66 set menu_color_normal=white/black 67 set menu_color_highlight=black/light-gray 68 if background_color 44,0,30; then 69 clear 70 fi 71 ### END /etc/grub.d/05_debian_theme ### 72 73 ### BEGIN /etc/grub.d/10_linux ### 74 function gfxmode { 75 set gfxpayload="${1}" 76 if [ "${1}" = "keep" ]; then 77 set vt_handoff=vt.handoff=7 78 else 79 set vt_handoff= 80 fi 81 } 82 if [ "${recordfail}" != 1 ]; then 83 if [ -e ${prefix}/gfxblacklist.txt ]; then 84 if hwmatch ${prefix}/gfxblacklist.txt 3; then 85 if [ ${match} = 0 ]; then 86 set linux_gfx_mode=keep 87 else 88 set linux_gfx_mode=text 89 fi 90 else 91 set linux_gfx_mode=text 92 fi 93 else 94 set linux_gfx_mode=keep 95 fi 96 else 97 set linux_gfx_mode=text 98 fi 99 export linux_gfx_mode 100 if [ "${linux_gfx_mode}" != "text" ]; then load_video; fi
#********************这是一个启动项，启动项0，红色的是启动项名字 101 menuentry 'Ubuntu，Linux 3.2.0-101-generic' --class ubuntu --class gnu-linux --class gnu --class os { 102 recordfail 103 gfxmode $linux_gfx_mode 104 insmod gzio 105 insmod part_msdos 106 insmod ext2 107 set root='(hd0,msdos7)' 108 search --no-floppy --fs-uuid --set=root dea69c19-08d2-433a-89b9-f917b6d5cce4 109 linux /boot/vmlinuz-3.2.0-101-generic root=UUID=dea69c19-08d2-433a-89b9-f917b6d5cce4 ro quiet splash $vt_handoff 110 initrd /boot/initrd.img-3.2.0-101-generic 111 }
#********************这是一个启动项，启动项1
112 menuentry 'Ubuntu, with Linux 3.2.0-101-generic (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os { 113 recordfail 114 insmod gzio 115 insmod part_msdos 116 insmod ext2 117 set root='(hd0,msdos7)' 118 search --no-floppy --fs-uuid --set=root dea69c19-08d2-433a-89b9-f917b6d5cce4 119 echo '载入 Linux 3.2.0-101-generic ...' 120 linux /boot/vmlinuz-3.2.0-101-generic root=UUID=dea69c19-08d2-433a-89b9-f917b6d5cce4 ro recovery nomodeset 121 echo '载入初始化内存盘...' 122 initrd /boot/initrd.img-3.2.0-101-generic 123 }
#********************这是一个启动项，启动项2
124 menuentry 'Ubuntu，Linux 3.19.0-68-generic' --class ubuntu --class gnu-linux --class gnu --class os {
125 recordfail
126 gfxmode $linux_gfx_mode
127 insmod gzio
128 insmod part_msdos
129 insmod ext2
130 set root='(hd0,msdos7)'
131 search --no-floppy --fs-uuid --set=root dea69c19-08d2-433a-89b9-f917b6d5cce4
132 linux /boot/vmlinuz-3.19.0-68-generic root=UUID=dea69c19-08d2-433a-89b9-f917b6d5cce4 ro quiet splash $vt_handoff
133 initrd /boot/initrd.img-3.19.0-68-generic
134 }
后边的代码太多删了
submenu "Previous Linux versions" 算一个，在启动时选择该项，能选择里面的启动内核
谨慎修改grub
