Short on space in /boot?

Edit /etc/initramfs-tools/initramfs.conf (Debian) and replace MODULES=dep with MODULES=dep. This will reduce the size of the initrd.img image by guessing modules to include.

#
# MODULES: [ most | netboot | dep | list ]
#
# most - Add most filesystem and all harddrive drivers.
#
# dep - Try and guess which modules to load.
#
# netboot - Add the base modules, network modules, but skip block devices.
#
# list - Only include modules from the 'additional modules' list
#

MODULES=dep

PS: Use at your own risk