The upgrade needs a total of 99.7 M free space on disk '/boot'.
Please free at least an additional 53.7 M of disk space on '/boot'.
You can remove old kernels using 'sudo apt autoremove', and you could also set COMPRESS=xz in /etc/initramfs-tools/initramfs.conf to reduce the size of your initramfs.
按照如下图示，执行命令：
- $ cd /boot/
- $ dpkg -l | grep linux-image #查看你机器上所有的内核
- $ uname -a #查看你当前所使用的内核
- $ sudo apt-get purge --remove 你没有使用的内核名称
