我从 Ubuntu 15.04 64 位升级到 15.10 64 位。之后内核显示的版本比安装的版本要旧：
$ uname -r
3.13.0-57-generic
即使安装了 4.2：
$ dpkg -l | grep linux-image
rc linux-image-3.19.0-15-generic 3.19.0-15.15 amd64 Linux kernel image for version 3.19.0 on 64 bit x86 SMP
rc linux-image-3.19.0-22-generic 3.19.0-22.22 amd64 Linux kernel image for version 3.19.0 on 64 bit x86 SMP
rc linux-image-3.19.0-28-generic 3.19.0-28.30 amd64 Linux kernel image for version 3.19.0 on 64 bit x86 SMP
ii linux-image-4.2.0-16-generic 4.2.0-16.19 amd64 Linux kernel image for version 4.2.0 on 64 bit x86 SMP
rc linux-image-extra-3.19.0-15-generic 3.19.0-15.15 amd64 Linux kernel extra modules for version 3.19.0 on 64 bit x86 SMP
rc linux-image-extra-3.19.0-22-generic 3.19.0-22.22 amd64 Linux kernel extra modules for version 3.19.0 on 64 bit x86 SMP
rc linux-image-extra-3.19.0-28-generic 3.19.0-28.30 amd64 Linux kernel extra modules for version 3.19.0 on 64 bit x86 SMP
ii linux-image-extra-4.2.0-16-generic 4.2.0-16.19 amd64 Linux kernel extra modules for version 4.2.0 on 64 bit x86 SMP
ii linux-image-generic 4.2.0.16.18 amd64 Generic Linux kernel image
尝试按照其他线程重新安装 linux-general，但没有成功：
$ sudo apt-get install --reinstall linux-generic linux-headers-generic linux-image-generic
[sudo] password for chris:
Reading package lists... Done
Building dependency tree
Reading state information... Done
0 upgraded, 0 newly installed, 3 reinstalled, 0 to remove and 0 not upgraded.
Need to get 0 B/6,658 B of archives.
After this operation, 0 B of additional disk space will be used.
(Reading database ... 60056 files and directories currently installed.)
Preparing to unpack .../linux-generic_4.2.0.16.18_amd64.deb ...
Unpacking linux-generic (4.2.0.16.18) over (4.2.0.16.18) ...
Preparing to unpack .../linux-headers-generic_4.2.0.16.18_amd64.deb ...
Unpacking linux-headers-generic (4.2.0.16.18) over (4.2.0.16.18) ...
Preparing to unpack .../linux-image-generic_4.2.0.16.18_amd64.deb ...
Unpacking linux-image-generic (4.2.0.16.18) over (4.2.0.16.18) ...
Setting up linux-image-generic (4.2.0.16.18) ...
Setting up linux-headers-generic (4.2.0.16.18) ...
Setting up linux-generic (4.2.0.16.18) ...
我已重启多次，但仍然没有任何反应。
我该怎么做才能正确安装内核？它阻止我运行 iptables：
$ sudo iptables -L
modprobe: ERROR: ../libkmod/libkmod.c:578 kmod_search_moddep() could not open moddep file '/lib/modules/3.13.0-57-generic/modules.dep.bin'
iptables v1.4.21: can't initialize iptables table `filter': Table does not exist (do you need to insmod?)
Perhaps iptables or your kernel needs to be upgraded.
任何想法都值得赞赏。如果相关的话，这是在 DigitalOcean droplet 上。谢谢。
答案1
看来您的内核 4.2 已正确安装（如ii软件包名称左侧所示）。也许您只需要更新 grub 配置以将新内核考虑在内？
您是否尝试过该sudo update-grub命令，然后重新启动？
答案2
事实证明，这肯定是其他问题的重复。我一直在执行命令行重启，但没有任何效果。实际上，电源循环可以很好地解决问题。
不记得以前见过这种行为，但也许这是 DigitalOcean/VM 或其他什么东西所特有的。
感谢您的建议！