To increase the image file size for Linux Deploy, you first need to expand the existing image, and then expand the file system to a new size. For example, to increase the image by 3000 MB, you need to do the following:
dd if=/dev/zero bs=1048576 count=3000 >> /mnt/sdcard/linux.img
e2fsck -f /mnt/sdcard/linux.img
You must first make a backup copy of the image.