resizing qemu image

lets add 10 GiB

qemu-img resize ubuntu-server.img +10G

then

image

nice work!

fixing

if your ubuntu use LVM2, Use this command

image

then, run

sudo lvextend -l +100%FREE /dev/ubuntu-vg/ubuntu-lv
sudo e2fsck -f /dev/ubuntu-vg/ubuntu-lv
sudo resize2fs /dev/ubuntu-vg/ubuntu-lv