一、问题
ununtu经常自动升级，或者是我们在update时，系统自动升级内核。此时会导致较高版本的内核与系统相互矛盾，而导致卡机等问题。此时需要对多余内核进行设置为默认内核或者将不正确内核删除。
两种方法:设置默认内核 ;删除内核。
二、设置默认内核
1、查看已经安装内核
dpkg --get-selections |grep linux-image
输出为：
linux-image-5.4.0-100-generic deinstall
linux-image-5.4.0-107-generic install
linux-image-5.4.0-109-generic install
linux-image-5.4.0-42-generic deinstall
linux-image-5.4.0-70-generic deinstall
linux-image-generic-hwe-18.04 install
其中install是已经安装的，但是deinstall是已经卸载的
2、查看内核启动顺序
grep menuentry /boot/grub/grub.cfg
输出为：
if [ x"${feature_menuentry_id}" = xy ]; then
menuentry_id_option="--id"
menuentry_id_option=""
export menuentry_id_option
menuentry 'Ubuntu' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-simple-93a5fee9-0321-409e-bac2-50327a6c34ee' {
submenu 'Advanced options for Ubuntu' $menuentry_id_option 'gnulinux-advanced-93a5fee9-0321-409e-bac2-50327a6c34ee' {
menuentry 'Ubuntu, with Linux 5.4.0-109-generic' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-5.4.0-109-generic-advanced-93a5fee9-0321-409e-bac2-50327a6c34ee' {
menuentry 'Ubuntu, with Linux 5.4.0-109-generic (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-5.4.0-109-generic-recovery-93a5fee9-0321-409e-bac2-50327a6c34ee' {
menuentry 'Ubuntu, with Linux 5.4.0-107-generic' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-5.4.0-107-generic-advanced-93a5fee9-0321-409e-bac2-50327a6c34ee' {
menuentry 'Ubuntu, with Linux 5.4.0-107-generic (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-5.4.0-107-generic-recovery-93a5fee9-0321-409e-bac2-50327a6c34ee' {
menuentry 'Ubuntu, with Linux 5.4.0-91-generic' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-5.4.0-91-generic-advanced-93a5fee9-0321-409e-bac2-50327a6c34ee' {
menuentry 'Ubuntu, with Linux 5.4.0-91-generic (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-5.4.0-91-generic-recovery-93a5fee9-0321-409e-bac2-50327a6c34ee' {
menuentry 'Ubuntu, with Linux 5.4.0-89-generic' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-5.4.0-89-generic-advanced-93a5fee9-0321-409e-bac2-50327a6c34ee' {
menuentry 'Ubuntu, with Linux 5.4.0-89-generic (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-5.4.0-89-generic-recovery-93a5fee9-0321-409e-bac2-50327a6c34ee' {
menuentry 'Windows Boot Manager (on /dev/nvme0n1p1)' --class windows --class os $menuentry_id_option 'osprober-efi-CA62-4E14' {
menuentry 'System setup' $menuentry_id_option 'uefi-firmware' {
可以看出我们系统默认启动Ubuntu, with Linux 5.4.0-109-generic内核，但是我们正常可用的是Ubuntu, with Linux 5.4.0-91-generic内核
3、修改内核启动顺序
sudo gedit /etc/default/grub
打开/etc/default/grub文件
将GRUB_DEFAULT=0注释，新增
GRUB_DEFAULT=“Advanced options for Ubuntu>Ubuntu, with Linux 5.4.0-91-generic”
注意：这里面的版本号选择自己电脑对应版本
# If you change this file, run 'update-grub' afterwards to update
# /boot/grub/grub.cfg.
# For full documentation of the options in this file, see:
# info -f grub -n 'Simple configuration'
#GRUB_DEFAULT=0
GRUB_DEFAULT="Advanced options for Ubuntu>Ubuntu, with Linux 5.4.0-91-generic"
GRUB_TIMEOUT_STYLE=hidden
GRUB_TIMEOUT=10
GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash i8042.dumbkbd"
GRUB_CMDLINE_LINUX=""
# Uncomment to enable BadRAM filtering, modify to suit your needs
# This works with Linux (no patch required) and with any kernel that obtains
# the memory map information from GRUB (GNU Mach, kernel of FreeBSD ...)
#GRUB_BADRAM="0x01234567,0xfefefefe,0x89abcdef,0xefefefef"
# Uncomment to disable graphical terminal (grub-pc only)
#GRUB_TERMINAL=console
# The resolution used on graphical terminal
# note that you can use only modes which your graphic card supports via VBE
# you can see them in real GRUB with the command `vbeinfo'
#GRUB_GFXMODE=640x480
# Uncomment if you don't want GRUB to pass "root=UUID=xxx" parameter to Linux
#GRUB_DISABLE_LINUX_UUID=true
# Uncomment to disable generation of recovery mode menu entries
#GRUB_DISABLE_RECOVERY="true"
# Uncomment to get a beep at grub start
#GRUB_INIT_TUNE="480 440 1"
4、重启
三、删除内核
1、查看已经安装内核
dpkg --get-selections |grep linux
输出为：
binutils-x86-64-linux-gnu install
console-setup-linux install
libselinux1:amd64 install
linux-base install
linux-firmware install
linux-generic-hwe-18.04 install
linux-headers-5.4.0-107-generic install
linux-headers-5.4.0-109-generic install
linux-headers-generic-hwe-18.04 install
linux-hwe-5.4-headers-5.4.0-100 install
linux-hwe-5.4-headers-5.4.0-107 install
linux-hwe-5.4-headers-5.4.0-109 install
linux-hwe-5.4-headers-5.4.0-42 install
linux-hwe-5.4-headers-5.4.0-70 install
linux-image-5.4.0-100-generic deinstall
linux-image-5.4.0-107-generic install
linux-image-5.4.0-109-generic install
linux-image-5.4.0-42-generic deinstall
linux-image-5.4.0-70-generic deinstall
linux-image-generic-hwe-18.04 install
linux-libc-dev:amd64 install
linux-modules-5.4.0-100-generic deinstall
linux-modules-5.4.0-107-generic install
linux-modules-5.4.0-109-generic install
linux-modules-5.4.0-42-generic deinstall
linux-modules-5.4.0-70-generic deinstall
linux-modules-extra-5.4.0-100-generic deinstall
linux-modules-extra-5.4.0-107-generic install
linux-modules-extra-5.4.0-109-generic install
linux-modules-extra-5.4.0-42-generic deinstall
linux-modules-extra-5.4.0-70-generic deinstall
linux-signed-generic-hwe-18.04 install
linux-sound-base install
pptp-linux install
syslinux install
syslinux-common install
syslinux-legacy install
util-linux install
2、删除内核
sudo apt-get remove \
linux-headers-5.4.0-100 \
linux-headers-5.4.0-100-generic \
linux-image-5.4.0-107-generic \
linux-modules-5.4.0-107-generic \
linux-modules-extra-5.4.0-107-generic
卸载后，再重新检查一下现有的内核，deinstall就是卸载完成的
dpkg --get-selections | grep linux
3、更新GRUB
sudo update-grub
这种方式我没有成功，但是第一种我成功了。