Can't Use apt i.e. /boot is 100% full

1. Get the list of kernel images

Get the list of kernel images and determine what you can do without. This command will show installed kernels except the currently running one

$ sudo dpkg --list 'linux-image*'|awk '{ if ($1=="ii") print $2}'|grep -v `uname -r`

You will get the list of images somethign like below:

linux-image-3.19.0-25-generic
linux-image-3.19.0-56-generic
linux-image-3.19.0-58-generic
linux-image-3.19.0-59-generic
linux-image-3.19.0-61-generic
linux-image-3.19.0-65-generic
linux-image-extra-3.19.0-25-generic
linux-image-extra-3.19.0-56-generic
linux-image-extra-3.19.0-58-generic
linux-image-extra-3.19.0-59-generic
linux-image-extra-3.19.0-61-generic

2. Prepare Delete

Craft a command to delete all files in /boot for kernels that don't matter to you using brace expansion to keep you sane. Remember to exclude the current and two newest kernel images. From above Example, it's

sudo rm -rf /boot/*-3.19.0-{25,56,58,59,61,65}-*

3. Clean up what's making apt grumpy about a partial install.

sudo apt-get -f install

4. Autoremove

Finally, autoremove to clear out the old kernel image packages that have been orphaned by the manual boot clean.

sudo apt-get autoremove

5. Update Grub

sudo update-grub

6. Now you can update, install packages

sudo apt-get update