Gfilui

I currently have Q4os installed.

What command can I use to install Lubuntu from files on USB? I can't boot install from USB and mini install doesn't have wireless internet installed.

You may, using debootstrap. This is not for the faint of heart, as it is mostly a manual procedure, but it's absolutely possible.

First you will have to make space. Shrink one of the existing partitions, so you have at least a gigabyte or three for Ubuntu. This can be increased later, when you have booted into Ubuntu, and are ready to remove your current OS. gparted is a nice GUI tool for working with partitions.

Next, mount your new partition somewhere nice. I will use /mnt for this in this text.

Also run the following command, and save the UUID for later! Substitute sdb1 for whatever partition you set up.

$ sudo blkid /dev/sdb1
/dev/sdb1: LABEL="ubuntu" UUID="a15e52e5-a5e3-4643-a657-43ce87f9aa00" TYPE="ext4"

Getting debootstrap

At this stage I assumed /mnt/ is mounted.

First step is to download debootstrap. At the time of writing, debootstrap_1.0.95.tar.gz is the latest version:

[/tmp]$ wget "http://ports.ubuntu.com/ubuntu-ports/pool/main/d/debootstrap/debootstrap_1.0.95.tar.gz"
[/tmp]$ tar zxf debootstrap_1.0.95.tar.gz 
[/tmp]$ cd debootstrap-1.0.95/
[/tmp/debootstrap-1.0.95]$ export DEBOOTSTRAP_DIR=`pwd`
[/tmp/debootstrap-1.0.95]$ sudo DEBOOTSTRAP_DIR=`pwd` ./debootstrap --arch=amd64 xenial /mnt http://archive.ubuntu.com/ubuntu
[removed lots of output of debootstrap fetching packages]

This step takes some time, as the base system is downloaded and unpacked into /mnt. It should end with I: Base system installed successfully.

Then we need to bind mount some system directories, so information about the machine is available inside the chroot:

# sudo mount -o bind /dev /mnt/dev
# sudo mount -o bind /dev/pts /mnt/dev/pts
# sudo mount -t sysfs /sys /mnt/sys
# sudo mount -t proc /proc /mnt/proc

chroot into the new system

[/tmp/debootstrap-1.0.95]$ sudo chroot /mnt
root@hannah:/#

This is a functioning Ubuntu system, albeit a minimal one.
First step is probably to install a few packages, such as nano.
You will get error messages complaining that devices are unavailable and so forth. This is normal. Ignore them.

All commands from now on is run inside the chroot environment.

Mount the virtual /proc and /sys fs:
# mount -t proc proc /proc
# mount -t sysfs sysfs /sys

Configure fstab

The fstab is blank. Edit it with nano:

# nano /etc/fstab

Add a line like

UUID=a15e52e5-a5e3-4643-a657-43ce87f9aa00 / ext4 errors=remount-ro 0 1

where the UUID is the one you saved above.

Update your system

# echo "deb http://security.ubuntu.com/ubuntu xenial-security main" > /etc/apt/sources.list
# echo "deb http://archive.ubuntu.com/ubuntu/ xenial-backports main restricted universe multiverse" >> /etc/apt/sources.list
# echo "deb http://archive.ubuntu.com/ubuntu/ xenial main restricted universe multiverse" >> /etc/apt/sources.list
# apt-get update && apt-get upgrade

Time to install a kernel!

# apt-cache search linux-image

will list available kernels. Pick a suitable one. For me this was linux-image-4.8.0-58-generic, which was installed with

# apt-get install linux-image-4.8.0-58-generic

This should ask you where you want to install the bootloader. This is typically the main drive, /dev/sda or similar. This will overwrite your current bootloader and make your current system unbootable!

Adding a user

# adduser foo
 ##Answer adduser with password, name and so on
# usermod -aG sudo username

The last command will add sudo permissions for the user.

Misc things to configure

You probably want to configure those items.

Timezone:

# dpkg-reconfigure tzdata

Locales:

# dpkg-reconfigure locales

Install lubuntu-desktop

# apt-get lubuntu-desktop

This will install the meta-package lubuntu-desktop which depends on all you need for a standard lubuntu desktop. This takes a little while, as it is many packages. This will probably fail, as blueman will refuse to work without a running, proper system. Ignore it, and remove it with apt-get remove blueman.

This should be more or less it. Reboot into your new system, and log in.