Ubuntu 16.04使用purge-old-kernels脚本卸载旧内核：
purge-old-kernels在byobu软件包中，首先，安装byobu：
$ sudo apt install byobu
运行purge-old-kernels卸载旧内核：
$ sudo purge-old-kernels
为了保险它会保留最新的两个Linux内核。
purge-old-kernels脚本：https://raw.githubusercontent.com/dustinkirkland/byobu/master/usr/bin/purge-old-kernels
#!/bin/sh
#
# purge-old-kernels - remove old kernel packages
# Copyright (C) 2012 Dustin Kirkland <kirkland@ubuntu.com>
#
# Authors: Dustin Kirkland <kirkland@ubuntu.com>
# Kees Cook <kees@ubuntu.com>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, version 3 of the License.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
# Ensure we're running as root
if [ "$(id -u)" != 0 ]; then
echo "ERROR: This script must run as root. Hint..." 1>&2
echo " sudo $0 $@" 1>&2
exit 1
fi
# NOTE: This script will ALWAYS keep the currently running kernel
# NOTE: Default is to keep 2 more, user overrides with --keep N
KEEP=2
# NOTE: Any unrecognized option will be passed straight through to apt
APT_OPTS=
while [ ! -z "$1" ]; do
case "$1" in
--keep)
# User specified the number of kernels to keep
KEEP="$2"
shift 2
;;
*)
APT_OPTS="$APT_OPTS $1"
shift 1
;;
esac
done
# Build our list of kernel packages to purge
CANDIDATES=$(ls -tr /boot/vmlinuz-* | head -n -${KEEP} | grep -v "$(uname -r)$" | cut -d- -f2- | awk '{print "linux-image-" $0 " linux-headers-" $0}' )
for c in $CANDIDATES; do
dpkg-query -s "$c" >/dev/null 2>&1 && PURGE="$PURGE $c"
done
if [ -z "$PURGE" ]; then
echo "No kernels are eligible for removal"
exit 0
fi
apt $APT_OPTS remove --purge $PURGE