Installing Linux from Linux

I often be underwhelmed by Linux's usb disk creator app, both the KDE and GTK versions.

• It crashes.
• It requires a FAT32 partition ?!?!
• It boots to a noddy try me out application.
• Its an annoyance on the way to installing Linux.

I've done netboot installs, just to avoid the USB creator stuff. Netboot is cool if you have a few PCs to install but a headache if you only have one to do.

This trick I've just discovered saves you from all that, you install Linux from Linux directly, no downloading ISOs nor reboots.  You can install Linux on to any HD that is connected to your current system.

In this case I wanted to install a full Linux system onto a 128GB USB3 drive I'd just purchased for the princley sum of 39€ & 80 cents.

This is the process, in my case, all done from a running Ubuntu system installing Ubuntu.

Create the partitions as you like them

Use whatever tools you prefer.
Personally I like to keep it simple and have everything on one partition.You have so many options for the tools to use to setup partitions in Linux.  Unlike when you install from a pen drive where you get only which one comes with the installer.

Rather than GUI tools I prefer simply...

fdisk /dev/sdb
mkfs.ext4 /dev/sdb1

since this is what I'm familiar with.

Install a base Linux to the partition

mount /dev/sdb1 /mnt/installer
apt-get install debootstrap
debootstrap trusty /mnt/installer

Where "trusty" is a string I had to hunt around the internet to find out.

This page helped http://packages.ubuntu.com/search?keywords=debootstrap

debootstrap installs a minimal Linux to the HD. Just enough for apt-get to be useful. No kernel or bootloader at this stage.  I notice debootstrap what lxc uses to setup a base container.

Create a chroot and use familiar tools to install the system

mount --bind /dev /mnt/installer/dev
mount --bind /dev/pts /mnt/installer/dev/pts
mount -t proc proc /mnt/installer/proc
mount -t sysfs sys /mnt/installer/sys
chroot /mnt/installer


Now your in a chroot where apt-get works and you can setup the system as you like it.  The following for a base Ubuntu desktop.  With this method you can install a simpler system if you prefer.

apt-get update
apt-get install language-pack-en-base
apt-get upgrade

dpkg-reconfigure tzdata
apt-get install grub-pc linux-image
apt-get install ubuntu-desktop ubuntu-standard

N.B. grub pops up a question asking where you want to install it, be careful not to mess with the system you are running on.  The chroot is not a "jail" you can still do damage as root from where you are.

In the chroot you can also add a user (useradd), set the root password (passwd), change hostname (vi /etc/hostname) and/or do whatever setup you feel like before you boot the system's kernel for the first time.

That's it. You now have Linux installed on the drive.  Without having to shutdown the current system.

You can boot from this Disk now or, as in my case unmount the drive and use it to boot a different machine.

This blog post is pretty much copied from halfway down this page.

https://help.ubuntu.com/community/Installation/FromLinux#Without_CD


N.B. after setting up a system, before logging in for the first time. I'd recommend trying to remove all the advertising nonsense from the CLI.

apt-get remove unity-scope-musicstores
apt-get remove unity-scope-video-remote
apt-get remove unity-scope-yelp
apt-get remove unity-scope-home
apt-get remove unity-scope-gdrive

To ditch that Amazon advertising that Ubuntu installs by default is now rather difficult you have to get rid of the whole webapps thing which is a shame.

apt-get remove unity-webapps-service
apt-get remove unity-webapps-qml

And of course you can now triumphantly

apt-get remove usb-creator-gtk