当我使用 apt-get 时dist-upgrade，可靠地生成了几个 4.x 内核。
jeff@starshine:boot $ ls -lt
total 135676
-rw-r--r-- 1 root root 68578468 Dec 23 09:27 initrd.img-5.0.0-37-generic
-rw-r--r-- 1 root root 18585279 Dec 23 09:26 initrd.img-4.4.0-59-generic
-rw-r--r-- 1 root root 18585112 Dec 23 09:26 initrd.img-4.10.0-42-generic
-rw-r--r-- 1 root root 18585676 Dec 23 09:26 initrd.img-4.13.0-46-generic
drwxr-xr-x 5 root root 1024 Dec 12 12:56 grub
-rw------- 1 root root 8806136 Nov 13 22:36 vmlinuz-5.0.0-37-generic
-rw-r--r-- 1 root root 224480 Nov 13 20:35 config-5.0.0-37-generic
-rw------- 1 root root 4440495 Nov 13 20:35 System.map-5.0.0-37-generic
-rw-r--r-- 1 root root 182704 Jan 28 2016 memtest86+.bin
-rw-r--r-- 1 root root 184380 Jan 28 2016 memtest86+.elf
-rw-r--r-- 1 root root 184840 Jan 28 2016 memtest86+_multiboot.bin
drwx------ 2 root root 12288 Dec 17 2015 lost+found
drwx------ 3 root root 4096 Jan 1 1970 efi
jeff@starshine:boot $
有时这会导致升级空间不足。4.x 内核似乎不再存在于我的机器上：
jeff@starshine:boot $ dpkg --list | grep linux- | grep -Ev '^rc'
ii binutils-x86-64-linux-gnu 2.32-7ubuntu4 amd64 GNU binary utilities, for x86-64-linux-gnu target
ii linux-base 4.5ubuntu1 all Linux image base package
ii linux-firmware 1.178.7 all Firmware for Linux kernel drivers
ii linux-generic 5.0.0.37.39 amd64 Complete Generic Linux kernel and headers
ii linux-headers-5.0.0-37 5.0.0-37.40 all Header files related to Linux kernel version 5.0.0
ii linux-headers-5.0.0-37-generic 5.0.0-37.40 amd64 Linux kernel headers for version 5.0.0 on 64 bit x86 SMP
ii linux-headers-generic 5.0.0.37.39 amd64 Generic Linux kernel headers
ii linux-image-5.0.0-37-generic 5.0.0-37.40 amd64 Signed kernel image generic
ii linux-image-generic 5.0.0.37.39 amd64 Generic Linux kernel image
ii linux-libc-dev:amd64 5.0.0-37.40 amd64 Linux Kernel Headers for development
ii linux-modules-5.0.0-37-generic 5.0.0-37.40 amd64 Linux kernel extra modules for version 5.0.0 on 64 bit x86 SMP
ii linux-modules-extra-5.0.0-37-generic 5.0.0-37.40 amd64 Linux kernel extra modules for version 5.0.0 on 64 bit x86 SMP
ii linux-signed-generic 5.0.0.37.39 amd64 Complete Signed Generic Linux kernel and headers (dummy transitional package)
ii linux-sound-base 1.0.25+dfsg-0ubuntu5 all base package for ALSA and OSS sound systems
ii syslinux-common 3:6.04~git20171011.af7e95c3+dfsg1-6 all collection of bootloaders (common)
ii syslinux-legacy 2:3.63+dfsg-2ubuntu9 amd64 Bootloader for Linux/i386 using MS-DOS floppies
jeff@starshine:boot $
仔细检查 grub 配置，我找不到导致创建这些额外图像的原因。有人可以提供一些建议吗？