Ubuntu – How to increase the /boot partition size in Ubuntu 16.04?

Ok, i had the exact same problem at least 9-10 times each time i formatted my /home partition and the windows partition later.What i do every time is this:

1. mount the ubuntu live cd and try ubuntu
2. open terminal
3. sudo fdisk -l (that gives a list of partition)
4. sudo mount /dev/sdanumber_0f_disk_you_have_installed_the_ubuntu /mnt for example sudo mount /dev/sda2 /mnt

lets say number_0f_disk_you_have_installed_the_ubuntu=X

1. sudo mount /dev/sdaX /mnt/boot
2. sudo mount --bind /dev /mnt/dev/
3. sudo chroot /mnt
4. grub-install /dev/sda
5. sudo umount /mnt/dev
6. sudo umount /mnt
7. sudo reboot

sudo swapoff -a  
sudo cryptsetup resize cryptswap1 --size (in sectors)  
sudo mkswap /dev/mapper/cryptswap1  
sudo swapon -a  

If --size is left out, it will use the whole device.

UPDATE - Based on feedback. Reboot and make sure mint--vg-swap_1 is still 980M.
IF IT IS, do the steps below. -- Try manually increasing the size of the container first (I don't think that should have been necessary). Your comment says you are trying to make the swap 4G (+3G), so:

sudo swapoff -a  
sudo lvresize -L+3G /dev/mapper/mint--vg-swap_1
sudo cryptsetup resize cryptswap1 --size 7812500
sudo mkswap /dev/mapper/cryptswap1  
sudo swapon -a  

On the other hand, if mint--vg-swap_1 is now 4G, then run this (allow for the size of the header):

sudo swapoff -a  
sudo cryptsetup resize cryptswap1 --size 7808404   
sudo mkswap /dev/mapper/cryptswap1  
sudo swapon -a  

Reference