debian内核小版本升级(9.0->9.9)

执行lsb_release -a查看内核版本

root@xxxxxxx# lsb_release -a
No LSB modules are available.
Distributor ID: Debian
Description:    Debian GNU/Linux 9.0 (stretch)
Release:        9.0
Codename:       stretch

查看/etc/apt/sources.list，将其更新为想要版本的snapshot源，注意确认apt源的小版本号是否与预期相符

root@xxxxxxx# cat /etc/apt/sources.list
deb http://snapshot.apt.netease.com:8660/debian9.9 stretch main non-free contrib
deb-src http://snapshot.apt.netease.com:8660/debian9.9 stretch main non-free contrib

执行一次完整的 apt-get update && apt-get upgrade，安装过程中选择保持当前版本，存放位置默认/分区

Need to get 117 MB of archives.
After this operation, 863 kB of additional disk space will be used.
Do you want to continue? [Y/n] y

接着会让按章GURB，使用空格键(space)选中磁盘，然后使用Tab键选中OK，按下Enter确定即可

GRUB install

安装完成后可以再次查看版本

root@xxxxxxx# lsb_release -a
No LSB modules are available.
Distributor ID: Debian
Description:    Debian GNU/Linux 9.9 (stretch)
Release:        9.9
Codename:       stretch