[conspire] Debian, yes we can go quite small, unlike ... and Ubuntu 20.04 & UEFI & not

[Michael Paoli]

So, CABAL today ...

I did poke about at an Ubuntu 20.04 LTS install (from
ubuntu-20.04-desktop-amd64.iso) ... was curious about if it "insisted"
upon UEFI install or not.  So, poked about it on a Virtual Machine.
Already had a VM set to just run it live from the ISO, no other drive.
I just used that as a basis and slightly modified it:
added 8 GiB drive (virtual)
enabled boot menu to select boot device,
set it to default to trying the virtual drive first, before optical.
Well first glitch - it didn't want to install to 8 GiB drive - said
that was too small.  Bumped it up to 10 GiB - it took that.
Did pretty much default install.  And yes, by default, it did UEFI.
After bit 'o poking at it, brought it down, wiped the virtual drive
(actually truncated it to 0 length, then brought the logical to
10 GiB again - sparse file), went through install again, but this time
I didn't go with default partitioning.  I set up first partition as
/boot (ext2), then I gave it a swap partition (2 GiB), then the remainder as
/ (root) filesystem (ext4).  And then installed like that ...
And it did a quite standard/legacy install, no UEFI.
Ubuntu also requires 2 GiB of RAM to install (it's possible, but
painful, to work around that - but one won't end up with a very
functional result).

So, ... I was kind'a curious, ... Debian, ... I already have a relatively
minimal Debian VM.  I was kind'a curious how small I could take it down
to ... and not even going "all the way", but mostly whacking away at
the non-required and such.
Well, before making it too painful for myself, ... down to ...
# cat /etc/debian_version; swapoff -a; free; df -h -x devtmpfs -x  
tmpfs; dpkg -l | grep '^ii ' | wc -l
10.6
               total        used        free      shared  buff/cache    
available
Mem:         131272       38396        3648        1420       89228     
    86068
Swap:             0           0           0
Filesystem      Size  Used Avail Use% Mounted on
/dev/vda1       1.4G  693M  626M  53% /
143
#
Disk could of course be reduced further, maybe even memory a wee bit further.
The VM has 157696 KiB of RAM.
And, quite trimmed down the packages ...
# cd $(mktemp -d)
# >a && rm * && { (for deb in $(dpkg -l | awk '{if($1=="ii")print  
$2;}'); do set -- $(apt-cache show "$deb" | sed -ne 's/^Priority:  
\(..*\)$/\1/p;s/^Essential: \(..*\)$/\1/p;/^$/q'); if [ "$#" -eq 1 ];  
then echo "$deb" >> "$1"; elif [ "$#" -eq 2 ] && [ "$1" == "yes" ];  
then echo "$deb" >> essential; echo "$deb" >> "$2"; fi; done); wc -l  
*; }
   23 essential
   21 important
   87 optional
   33 required
    2 standard
  166 total
# (for p in $(cat essential); do fgrep -lx "$p" [!e]*; done) | sort -u
required
#
// All that remain that are Essential: yes are also Priority: required
# (for f in required important standard optional; do echo "$f" $(cat  
"$f") | fold -s -w 72; done) | sed -e 's/  *$//'
required apt base-files base-passwd bash bsdutils coreutils dash
debconf debianutils diffutils dpkg e2fsprogs findutils grep gzip
hostname init-system-helpers libc-bin libpam-modules:amd64
libpam-modules-bin libpam-runtime login mawk mount ncurses-base
ncurses-bin passwd perl-base sed sysvinit-utils tar tzdata util-linux
important adduser cpio cron debian-archive-keyring fdisk gpgv ifupdown
init iproute2 iputils-ping kmod logrotate netbase procps
readline-common sensible-utils systemd systemd-sysv tasksel
tasksel-data udev
standard gettext-base ucf
optional dmsetup e2fslibs:amd64 firmware-linux-free gcc-8-base:amd64
grub-common grub-pc grub-pc-bin grub2-common initramfs-tools
initramfs-tools-core klibc-utils libacl1:amd64 libapparmor1:amd64
libapt-pkg5.0:amd64 libargon2-1:amd64 libattr1:amd64 libaudit-common
libaudit1:amd64 libblkid1:amd64 libbz2-1.0:amd64 libc6:amd64
libcap-ng0:amd64 libcap2:amd64 libcap2-bin libcom-err2:amd64
libcryptsetup12:amd64 libdb5.3:amd64 libdebconfclient0:amd64
libdevmapper1.02.1:amd64 libefiboot1:amd64 libefivar1:amd64
libelf1:amd64 libext2fs2:amd64 libfdisk1:amd64 libffi6:amd64
libfreetype6:amd64 libfuse2:amd64 libgcc1:amd64 libgcrypt20:amd64
libgmp10:amd64 libgnutls30:amd64 libgpg-error0:amd64 libhogweed4:amd64
libidn11:amd64 libidn2-0:amd64 libip4tc0:amd64 libjson-c3:amd64
libklibc:amd64 libkmod2:amd64 liblocale-gettext-perl liblz4-1:amd64
liblzma5:amd64 libmnl0:amd64 libmount1:amd64 libncurses6:amd64
libncursesw6:amd64 libnettle6:amd64 libp11-kit0:amd64 libpam0g:amd64
libpcre3:amd64 libpng16-16:amd64 libpopt0:amd64 libprocps7:amd64
libseccomp2:amd64 libselinux1:amd64 libsemanage-common
libsemanage1:amd64 libsepol1:amd64 libsmartcols1:amd64 libss2:amd64
libssl1.1:amd64 libstdc++6:amd64 libsystemd0:amd64 libtasn1-6:amd64
libtinfo6:amd64 libudev1:amd64 libunistring2:amd64 libuuid1:amd64
libxtables12:amd64 libzstd1:amd64 linux-base
linux-image-4.19.0-12-amd64 linux-image-amd64 lsb-base nvi xxd
zlib1g:amd64
# cat /etc/debian_version; swapoff -a; free; df -h -x devtmpfs -x  
tmpfs; dpkg -l | grep '^ii ' | wc -l
10.6
               total        used        free      shared  buff/cache    
available
Mem:         131272       38396        3648        1420       89228     
    86068
Swap:             0           0           0
Filesystem      Size  Used Avail Use% Mounted on
/dev/vda1       1.4G  693M  626M  53% /
143
#

So, ... Debian ...
well under 700 MiB of drive space,
157696 KiB of RAM
143 packages.

Ubuntu ... >8 GiB minimum for disk
> ~=2 GiB minimum for RAM
packages ... around 1,421
# dpkg -l | grep '^ii ' | wc -l; free; cat /etc/*{-release,_version}
1421
               total        used        free      shared  buff/cache    
available
Mem:        2035432      451968      345136        7352     1238328     
  1414436
Swap:       1999868           0     1999868
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=20.04
DISTRIB_CODENAME=focal
DISTRIB_DESCRIPTION="Ubuntu 20.04 LTS"
NAME="Ubuntu"
VERSION="20.04 LTS (Focal Fossa)"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 20.04 LTS"
VERSION_ID="20.04"
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
VERSION_CODENAME=focal
UBUNTU_CODENAME=focal
bullseye/sid
#

Yes, Debian - Universal Operating System ... over 59,000 ready-to-run
software packages ... but about 143 will do 'ya,
and 157696 KiB of RAM and about 700 MiB of drive to get 'ya started.