you boot volume has only 0 byte size

懒人方法：

uname -a

列出目前使用的内核

dpkg -l | grep linux-image

列出存在的linux内核

sudo apt-get purge linux-image-3.16.0-23-generic

purge 老的内核

如果想升级：

sudo apt-get dist-upgrade

以下是详细的方法：

To list all kernel:
dpkg --get-selections | grep "linux-image-[[:digit:]].*" | tr " " ";" | cut -d ";" -f1

简单的命令 dpkg -l |grep "linux-image"

The results looks somewhat like this:

linux-image-3.19.0-7-generic 
linux-image-3.18.0-13-generic  
linux-image-3.16.0-23-generic

Don't delete all kernels, only old ones!

Next let's remove the 3.16 kernel,
sudo apt-get purge linux-image-3.16.0-23-generic

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from: https://askubuntu.com/questions/746903/trouble-with-apt-get-install-due-to-multiple-linux-images

Alternative way:

An alternative is Synaptic

sudo apt-get install synaptic

After installing and running the program- search:

linux-image

Right-click a kernel and choose complete removal and finally click the Apply button to delete the kernel.

Repeat the search but this time for linux-header - you can delete the associated headers for the kernel image chosen previously.

Synaptic though will not attempt to verify what you are trying to remove... you could inadvertently delete your newest kernel - or even delete all of your kernels via this tool leaving you with an unbootable Ubuntu!.