Debian/Ubuntu 清理内核

不使用的内核占用空间，清理掉。

查看当前正在使用的内核

$ uname -r
4.19.0-0.bpo.2-amd64

列出所有已安装内核

$ dpkg -l | grep linux-
ii  firmware-linux-free              3.4                            all          Binary firmware for various drivers in the Linux kernel
ii  firmware-linux-nonfree           20190114-1~bpo9+2              all          Binary firmware for various drivers in the Linux kernel (meta-package)
ii  linux-base                       4.5                            all          Linux image base package
ii  linux-image-4.14.0-0.bpo.3-amd64 4.14.13-1~bpo9+1               amd64        Linux 4.14 for 64-bit PCs
ii  linux-image-4.19.0-0.bpo.2-amd64 4.19.16-1~bpo9+1               amd64        Linux 4.19 for 64-bit PCs (signed)
ii  linux-image-amd64                4.19+102~bpo9+1                amd64        Linux for 64-bit PCs (meta-package)

卸载旧内核

$ sudo apt purge linux-image-4.14.0-0.bpo.3-amd64

更新 grub

$ sudo update-grub