通过dpkg --list查看所有安装的软件

root@as-virtual-machine:/usr/src# dpkg --list

卸载自带浏览器firefox

执行如下代码

root@as-virtual-machine:/usr/src# dpkg --get-selections |grep firefox
firefox						install
firefox-locale-en				install
root@as-virtual-machine:/usr/src# sudo apt-get purge firefox firefox-locale-en

效果如下，减少了234MB空间

Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following packages will be REMOVED:
  firefox* firefox-locale-en*
0 upgraded, 0 newly installed, 2 to remove and 16 not upgraded.
After this operation, 234 MB disk space will be freed.
Do you want to continue? [Y/n] Y
(Reading database ... 164275 files and directories currently installed.)
Removing firefox (98.0.1+build2-0ubuntu0.20.04.1) ...
Removing firefox-locale-en (98.0.1+build2-0ubuntu0.20.04.1) ...
Processing triggers for mime-support (3.64ubuntu1) ...
Processing triggers for hicolor-icon-theme (0.17-2) ...
Processing triggers for gnome-menus (3.36.0-1ubuntu1) ...
Processing triggers for man-db (2.9.1-1) ...
Processing triggers for desktop-file-utils (0.24-1ubuntu3) ...
(Reading database ... 164176 files and directories currently installed.)
Purging configuration files for firefox (98.0.1+build2-0ubuntu0.20.04.1) ...

卸载gedit

root@as-virtual-machine:/home/as# apt-get -y purge gedit
root@as-virtual-machine:/home/as# apt-get -y purge gedit-common
root@as-virtual-machine:/home/as# apt-get -y purge gir1.2-gtksource-4 libamtk-5-0 libamtk-5-common libtepl-4-0 python3-gi-cairo

卸载evince

root@as-virtual-machine:/home/as#  apt-get remove --purge evince
root@as-virtual-machine:/home/as# apt-get -y purge evince-common libdjvulibre-text libdjvulibre21 libevdocument3-4 libevview3-3 libgspell-1-2 libgspell-1-common libkpathsea6 libspectre1 libsynctex2

其他

apt-get purge mdadm \
    git \
    acpid \
    vim* \
    ubuntu-cloudimage-keyring \
    ubuntu-core-launcher \
    software-properties-common \
    lxc* \
    lxd* \
    perl

apt-get autoremove