Stop duplicating kernel and initrd files in the kernel snap, use symlinks instead - as a side effect we trim +10MB from the kernel snap: Before: $ ls -la squashfs-root/ total 27604 drwxrwxr-x 5 flag flag 4096 mar 22 12:20 . drwxr-xr-x 29 flag flag 4096 mar 22 12:21 .. -rw-rw-r-- 2 flag flag 6531440 mar 22 12:20 bzImage-4.9.0+ drwxrwxr-x 36 flag flag 4096 mar 22 12:20 firmware -rw-rw-r-- 2 flag flag 5807334 mar 22 12:20 initrd-4.9.0+.img -rw-rw-r-- 2 flag flag 5807334 mar 22 12:20 initrd.img -rw-rw-r-- 2 flag flag 6531440 mar 22 12:20 kernel.img drwxrwxr-x 2 flag flag 4096 mar 22 12:20 meta drwxrwxr-x 3 flag flag 4096 mar 22 12:20 modules -rw-rw-r-- 1 flag flag 3559958 mar 22 12:20 System.map-4.9.0+ With this change: $ ls -la squashfs-root/ total 15552 drwxrwxr-x 5 flag flag 4096 mar 22 12:12 . drwxr-xr-x 29 flag flag 4096 mar 22 12:13 .. -rw-rw-r-- 1 flag flag 6531216 mar 22 12:12 bzImage-4.9.0+ drwxrwxr-x 36 flag flag 4096 mar 22 12:12 firmware -rw-rw-r-- 1 flag flag 5806664 mar 22 12:12 initrd-4.9.0+.img lrwxrwxrwx 1 flag flag 17 mar 22 12:13 initrd.img -> initrd-4.9.0+.img lrwxrwxrwx 1 flag flag 14 mar 22 12:13 kernel.img -> bzImage-4.9.0+ drwxrwxr-x 2 flag flag 4096 mar 22 12:12 meta drwxrwxr-x 3 flag flag 4096 mar 22 12:12 modules -rw-rw-r-- 1 flag flag 3559958 mar 22 12:12 System.map-4.9.0+