Ubuntu 内核版本降级

1、背景介绍

经常使用Ubuntu 作为开发平台，有降低内核版本的需求。下面介绍 Ubuntu 怎么降级到指定的 Linux 内核版本。

2、实际操作

ubuntu@ubuntu:~/Downloads$ uname -r 
5.4.0-120-generic  # 默认内核版本是： 5.4.0-120  现更改内核版本为： 5.4.0-148

# 每个内核版本都有一个带 -generic 和不带 -generic 的内核头文件，对于同一版本内核的这两个文件
# 夹都只是头文件，并不是源代码。带有 -generic 的目录里面均是指向不带 -generic 文件夹内容的
# 符号链接
ubuntu@ubuntu:/lib/modules$ uname -r 
5.4.0-120-generic
ubuntu@ubuntu:/lib/modules$ cd 5.4.0-120-generic
ubuntu@ubuntu:/lib/modules/5.4.0-120-generic$ ls
build   kernel         modules.alias.bin  modules.builtin.bin      modules.dep      modules.devname  modules.softdep  modules.symbols.bin
initrd  modules.alias  modules.builtin    modules.builtin.modinfo  modules.dep.bin  modules.order    modules.symbols  vdso
ubuntu@ubuntu:/lib/modules/5.4.0-120-generic$ ls -l 
total 5812
lrwxrwxrwx  1 root root      40 6月  10  2022 build -> /usr/src/linux-headers-5.4.0-120-generic
drwxr-xr-x  2 root root    4096 6月  10  2022 initrd
drwxr-xr-x 17 root root    4096 6月  19  2022 kernel
-rw-r--r--  1 root root 1403204 6月  19  2022 modules.alias
-rw-r--r--  1 root root 1380114 6月  19  2022 modules.alias.bin
-rw-r--r--  1 root root    8105 6月  10  2022 modules.builtin
-rw-r--r--  1 root root   10257 6月  19  2022 modules.builtin.bin
-rw-r--r--  1 root root   63668 6月  10  2022 modules.builtin.modinfo
-rw-r--r--  1 root root  610840 6月  19  2022 modules.dep
-rw-r--r--  1 root root  853423 6月  19  2022 modules.dep.bin
-rw-r--r--  1 root root     330 6月  19  2022 modules.devname
-rw-r--r--  1 root root  219972 6月  10  2022 modules.order
-rw-r--r--  1 root root     947 6月  19  2022 modules.softdep
-rw-r--r--  1 root root  615433 6月  19  2022 modules.symbols
-rw-r--r--  1 root root  748480 6月  19  2022 modules.symbols.bin
drwxr-xr-x  3 root root    4096 6月  19  2022 vdso
ubuntu@ubuntu:/lib/modules/5.4.0-120-generic$ ls -l /usr/src/linux-headers-5.4.0-120-generic/
total 1612
drwxr-xr-x 3 root root    4096 6月  19  2022 arch
lrwxrwxrwx 1 root root      40 6月  10  2022 block -> ../linux-hwe-5.4-headers-5.4.0-120/block
lrwxrwxrwx 1 root root      40 6月  10  2022 certs -> ../linux-hwe-5.4-headers-5.4.0-120/certs
lrwxrwxrwx 1 root root      41 6月  10  2022 crypto -> ../linux-hwe-5.4-headers-5.4.0-120/crypto
lrwxrwxrwx 1 root root      48 6月  10  2022 Documentation -> ../linux-hwe-5.4-headers-5.4.0-120/Documentation
lrwxrwxrwx 1 root root      42 6月  10  2022 drivers -> ../linux-hwe-5.4-headers-5.4.0-120/drivers
lrwxrwxrwx 1 root root      37 6月  10  2022 fs -> ../linux-hwe-5.4-headers-5.4.0-120/fs
drwxr-xr-x 4 root root    4096 6月  19  2022 include
lrwxrwxrwx 1 root root      39 6月  10  2022 init -> ../linux-hwe-5.4-headers-5.4.0-120/init
lrwxrwxrwx 1 root root      38 6月  10  2022 ipc -> ../linux-hwe-5.4-headers-5.4.0-120/ipc
lrwxrwxrwx 1 root root      41 6月  10  2022 Kbuild -> ../linux-hwe-5.4-headers-5.4.0-120/Kbuild
lrwxrwxrwx 1 root root      42 6月  10  2022 Kconfig -> ../linux-hwe-5.4-headers-5.4.0-120/Kconfig
drwxr-xr-x 2 root root    4096 6月  19  2022 kernel
lrwxrwxrwx 1 root root      38 6月  10  2022 lib -> ../linux-hwe-5.4-headers-5.4.0-120/lib
lrwxrwxrwx 1 root root      43 6月  10  2022 Makefile -> ../linux-hwe-5.4-headers-5.4.0-120/Makefile
lrwxrwxrwx 1 root root      37 6月  10  2022 mm -> ../linux-hwe-5.4-headers-5.4.0-120/mm
-rw-r--r-- 1 root root 1620851 6月  10  2022 Module.symvers
lrwxrwxrwx 1 root root      38 6月  10  2022 net -> ../linux-hwe-5.4-headers-5.4.0-120/net
lrwxrwxrwx 1 root root      42 6月  10  2022 samples -> ../linux-hwe-5.4-headers-5.4.0-120/samples
drwxr-xr-x 8 root root   12288 6月  19  2022 scripts
lrwxrwxrwx 1 root root      43 6月  10  2022 security -> ../linux-hwe-5.4-headers-5.4.0-120/security
lrwxrwxrwx 1 root root      40 6月  10  2022 sound -> ../linux-hwe-5.4-headers-5.4.0-120/sound
drwxr-xr-x 3 root root    4096 6月  19  2022 tools
lrwxrwxrwx 1 root root      41 6月  10  2022 ubuntu -> ../linux-hwe-5.4-headers-5.4.0-120/ubuntu
lrwxrwxrwx 1 root root      38 6月  10  2022 usr -> ../linux-hwe-5.4-headers-5.4.0-120/usr
lrwxrwxrwx 1 root root      39 6月  10  2022 virt -> ../linux-hwe-5.4-headers-5.4.0-120/virt

# 查看已经安装的内核镜像
ubuntu@ubuntu:~$ dpkg --get-selections | grep linux-image
linux-image-4.18.0-15-generic			deinstall
linux-image-5.4.0-120-generic			install
linux-image-5.4.0-147-generic			install
linux-image-5.4.0-148-generic			install
linux-image-5.4.0-45-generic			deinstall
linux-image-5.4.0-47-generic			deinstall
linux-image-5.4.0-52-generic			deinstall
linux-image-5.4.0-53-generic			deinstall
linux-image-5.4.0-58-generic			deinstall
linux-image-5.4.0-60-generic			deinstall
linux-image-5.4.0-62-generic			deinstall
linux-image-5.4.0-65-generic			deinstall
linux-image-5.4.0-66-generic			deinstall
linux-image-5.4.0-67-generic			deinstall
linux-image-5.4.0-70-generic			deinstall
linux-image-5.4.0-72-generic			deinstall
linux-image-5.4.0-81-generic			deinstall
linux-image-5.4.0-89-generic			deinstall
linux-image-5.4.0-90-generic			deinstall
linux-image-5.4.0-91-generic			deinstall
linux-image-5.4.0-92-generic			deinstall
linux-image-generic-hwe-18.04			install
linux-image-unsigned-6.3.3-060303-generic	install

# 查看指定版本的内核包 ，我需要的是 ： 5.4.0-148
ubuntu@ubuntu:~$ apt-cache search linux | grep 5.4.0-148

linux-buildinfo-5.4.0-148-generic - Linux kernel buildinfo for version 5.4.0 on 64 bit x86 SMP
linux-buildinfo-5.4.0-148-lowlatency - Linux kernel buildinfo for version 5.4.0 on 64 bit x86 SMP
linux-cloud-tools-5.4.0-148-generic - Linux kernel version specific cloud tools for version 5.4.0-148
linux-cloud-tools-5.4.0-148-lowlatency - Linux kernel version specific cloud tools for version 5.4.0-148

linux-headers-5.4.0-148-generic - Linux kernel headers for version 5.4.0 on 64 bit x86 SMP

linux-headers-5.4.0-148-lowlatency - Linux kernel headers for version 5.4.0 on 64 bit x86 SMP
linux-hwe-5.4-cloud-tools-5.4.0-148 - Linux kernel version specific cloud tools for version 5.4.0-148
linux-hwe-5.4-headers-5.4.0-148 - Header files related to Linux kernel version 5.4.0
linux-hwe-5.4-tools-5.4.0-148 - Linux kernel version specific tools for version 5.4.0-148

linux-image-5.4.0-148-generic - Signed kernel image generic

linux-image-5.4.0-148-lowlatency - Signed kernel image lowlatency
linux-image-unsigned-5.4.0-148-generic - Linux kernel image for version 5.4.0 on 64 bit x86 SMP
linux-image-unsigned-5.4.0-148-lowlatency - Linux kernel image for version 5.4.0 on 64 bit x86 SMP
linux-modules-5.4.0-148-generic - Linux kernel extra modules for version 5.4.0 on 64 bit x86 SMP
linux-modules-5.4.0-148-lowlatency - Linux kernel extra modules for version 5.4.0 on 64 bit x86 SMP
linux-modules-extra-5.4.0-148-generic - Linux kernel extra modules for version 5.4.0 on 64 bit x86 SMP
linux-tools-5.4.0-148-generic - Linux kernel version specific tools for version 5.4.0-148
linux-tools-5.4.0-148-lowlatency - Linux kernel version specific tools for version 5.4.0-148

# 安装指定的内核版本
sudo apt-get install linux-headers-5.4.0-148-generic linux-image-5.4.0-148-generic

# 当前系统中内核的启动顺序
ubuntu@ubuntu:~$ grep menuentry /boot/grub/grub.cfg
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-79c7761d-9676-433e-884c-516b6c45d576' {
submenu 'Advanced options for Ubuntu' $menuentry_id_option 'gnulinux-advanced-79c7761d-9676-433e-884c-516b6c45d576' {
	menuentry 'Ubuntu, with Linux 6.3.3-060303-generic' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-6.3.3-060303-generic-advanced-79c7761d-9676-433e-884c-516b6c45d576' {
	menuentry 'Ubuntu, with Linux 6.3.3-060303-generic (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-6.3.3-060303-generic-recovery-79c7761d-9676-433e-884c-516b6c45d576' {
	menuentry 'Ubuntu, with Linux 5.4.0-148-generic' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-5.4.0-148-generic-advanced-79c7761d-9676-433e-884c-516b6c45d576' {
	menuentry 'Ubuntu, with Linux 5.4.0-148-generic (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-5.4.0-148-generic-recovery-79c7761d-9676-433e-884c-516b6c45d576' {
	menuentry 'Ubuntu, with Linux 5.4.0-147-generic' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-5.4.0-147-generic-advanced-79c7761d-9676-433e-884c-516b6c45d576' {
	menuentry 'Ubuntu, with Linux 5.4.0-147-generic (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-5.4.0-147-generic-recovery-79c7761d-9676-433e-884c-516b6c45d576' {
	menuentry 'Ubuntu, with Linux 5.4.0-120-generic' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-5.4.0-120-generic-advanced-79c7761d-9676-433e-884c-516b6c45d576' {
	menuentry 'Ubuntu, with Linux 5.4.0-120-generic (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-5.4.0-120-generic-recovery-79c7761d-9676-433e-884c-516b6c45d576' {
menuentry 'Memory test (memtest86+)' {
menuentry 'Memory test (memtest86+, serial console 115200)' {

# 修改内核启动顺序
sudo vim /etc/default/grub
第一步：GRUB_DEFAULT=0
第二步： GRUB_DEFAULT="Advanced options for Ubuntu>Ubuntu, with Linux 5.4.0-120-generic"
将 第一步 修改为 第二步

# 执行update-grub 命令更新启动配置
sudo update-grub

# 重启系统查看内核版本
ubuntu@ubuntu:~$ uname -r 
5.4.0-120-generic

#如果想要开机启动自由选择内核版本 请做如下配置
sudo vim /etc/default/grub
第一步 GRUB_TIMEOUT_STYLE=hidden
第一步 GRUB_TIMEOUT=0

第二步 # GRUB_TIMEOUT_STYLE=hidden
第二步 GRUB_TIMEOUT=10

第三步 执行update-grub 命令更新启动配置 sudo update-grub

将 第一步 修改为 第二步 然后执行 第三步

# 重启系统查看内核版本
ubuntu@ubuntu:~$ uname -r 
5.4.0-120-generic

# 查看当前系统版本信息
ubuntu@ubuntu:~$ cat /etc/os-release 
NAME="Ubuntu"
VERSION="18.04.2 LTS (Bionic Beaver)"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 18.04.2 LTS"
VERSION_ID="18.04"
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
VERSION_CODENAME=bionic
UBUNTU_CODENAME=bionic
ubuntu@ubuntu:~$ 
ubuntu@ubuntu:~$ uname -r 
5.4.0-120-generic