Not enough space in system disk, will cause cannot boot and many problems, there is a stupid but easy way to prevent, use fallocate to create a 1GB file, you can delete it to free the disk when there is urgent case.

fallocate command basic syntax :

fallocate -l Image_Size_Here /path/to/image.img

for example, create a 1GB file :

fallocate -l 1G test.img

reference link :