Small(er) Ubuntu Server 22.04 Install on Vultr

For my new Ubuntu Server deployment I decided to go with Intel High Frequency Vultr instance, mostly due to its larger disk allotment. However, going with default Vultr's deployment image, I ended up with 18 GB of disk occupied. And yes, I could have removed extra stuff I didn't need (e.g. /usr/local/cuda/ was the prime candidate). However, I decided to go a different route - manual installation.

Getting the Ubuntu ISO is easy enough as a wide selection is already available behind ISO Library tab on Server Image selection page. Combine that with noVNC console and you can just click your way through. However, one can also find Shell option within the Help menu giving you access to the bash prompt and allowing for more control.

While noVNC is decent, the lack of copy/paste makes it unwieldy when more then a few commands need to be entered. So, my first task was to SSH into the installation and continue from there. To do this, we have to allow for password login and set the password.

Terminal  Copy
sed -i 's/^#PermitRootLogin.*$/PermitRootLogin yes/' /etc/ssh/sshd_config
systemctl restart sshd
passwd

Now we can connect using any SSH client and do the rest of steps from there.

I like to start by setting a few variables. Here I needed only DISK and HOST.

Terminal  Copy
DISK=/dev/vda
HOST=ubuntu

Assuming this is a fresh VM, the disk should already be empty but I like to clean it again (just in case) and create a single partition. On servers I quite often skip swap partition and that's the case here too.

Terminal  Copy
blkdiscard -f $DISK
echo -e "o\nn\np\n1\n\n\nw" | fdisk $DISK
fdisk -l $DISK

Now we can format our partition and mount it into /mnt/install/.

Terminal  Copy
mkfs.ext4 ${DISK}1
mkdir /mnt/install
mount ${DISK}1 /mnt/install/

We will need to install debootstrap to get our installation going.

Terminal  Copy
apt update ; apt install --yes debootstrap

And now we can finally move installation files to our disk.

Terminal  Copy
debootstrap $(basename `ls -d /cdrom/dists/*/ | grep -v stable | head -1`) /mnt/install/

Before proceeding, we might as well update a few settings.

Terminal  Copy
echo $HOST > /mnt/install/etc/hostname
sed "s/ubuntu/$HOST/" /etc/hosts > /mnt/install/etc/hosts
sed '/cdrom/d' /etc/apt/sources.list > /mnt/install/etc/apt/sources.list
cp /etc/netplan/*.yaml /mnt/install/etc/netplan/

Finally we get to chroot into our newly installed system.

Terminal  Copy
mount --rbind /dev  /mnt/install/dev
mount --rbind /proc /mnt/install/proc
mount --rbind /sys  /mnt/install/sys
chroot /mnt/install \
    /usr/bin/env DISK=$DISK HOST=$HOST \
    bash --login

While optional, I like to update locale settings and set the time zone.

Terminal  Copy
locale-gen --purge "en_US.UTF-8"
update-locale LANG=en_US.UTF-8 LANGUAGE=en_US
dpkg-reconfigure --frontend noninteractive locales
dpkg-reconfigure tzdata

Installing kernel is next.

Terminal  Copy
apt update
apt install --yes --no-install-recommends linux-image-generic linux-headers-generic

Followed by our boot environment packages.

Terminal  Copy
apt install --yes initramfs-tools grub-pc

Setting FSTab will ensure disk is mounted once done.

Terminal  Copy
echo "PARTUUID=$(blkid -s PARTUUID -o value ${DISK}1) \
    / ext4 noatime,nofail,x-systemd.device-timeout=5s 0 1" > /etc/fstab
cat /etc/fstab

Of course, boot wouldn't be possible without getting images ready.

Terminal  Copy
KERNEL=`ls /usr/lib/modules/ | cut -d/ -f1 | sed 's/linux-image-//'`
update-initramfs -u -k $KERNEL

And finally, boot needs Grub installed to MBR.

Terminal  Copy
update-grub
grub-install ${DISK}

While we could boot our system already, it's a bit too bare for my taste so I'll add a basic set of packages.

Terminal  Copy
apt install --yes ubuntu-server-minimal man

Once done, a small update will not hurt.

Terminal  Copy
apt update ; apt dist-upgrade --yes

Of course, we need to ensure we can boot into our system. While one could use passwd to set the root password, I like to use keys for access.

Terminal  Copy
mkdir /root/.ssh
echo 'ssh-ed25519 AAAA...' > /root/.ssh/authorized_keys
chmod 600 -R /root/.ssh

With all set, we can exit our chroot environment.

Terminal  Copy
exit

We might as well unmount our custom install.

Terminal  Copy
mount | tac | awk '/\/mnt/ {print $3}' | xargs -i{} umount -lf {}

And finally we get to reboot. Please note that you should also go to VM Settings and unmount custom ISO to avoid getting into installation again.

Terminal  Copy
reboot

If all steps worked, you will face a pristine Ubuntu installation measuring something around 5 GB. To make it even smaller, one can turn off the swap.

Terminal  Copy
swapoff -a
vi /etc/fstab
rm /swapfile

Regardless, your system is now ready for abuse. :)