How To: Installing BackTrack 4 R1 to a USB Flash Drive

Introduction:

In this tutorial you will learn how to install the latest version of BackTrack (BackTrack 4 R1) to your USB flash drive. Not only will you be able to boot BackTrack off of a flash drive, but it will also allow you to have persistent changes. This tutorial will also work for previous versions of BackTrack.

Tools and Material:

• USB Flash Drive – 8GB minimum
• DVD of BackTrack 4 R1 (or previous version)

The reason why we recommend an 8GB flash drive is that after everything is installed from the disk, you wouldn’t have much room for installing anything additional if you were to using a 4GB flash drive.

Partitioning the Flash Drive:

All of this tutorial will be done from the command line. So the first step is to pop in the disk and flash drive and select the first option when you are greeted by the BackTrack boot up menu. This will eventually leave you with a command prompt, which is where we will begin.
Now that we have a prompt, we must determine which drive our flash drive is. We accomplish this by running the command:

dmesg | egrep hd.\|sd.

This will give us a list of all drives on the machine. From there you need to select which one is yours. I will use sda in my examples, but yours may be different and you should substitute as necessary.
We will be using fdisk to create the partitions for our Flash Drive.

fdisk /dev/sda

Delete the existing partitions, there may be more than 1. Input the commands that are bolded.

Command (m for help): d
Partition number (1-4): 1

Create the first partition

Command (m for help): n
Command action
e   extended
p   primary partition (1-4)
p
Partition number (1-4): 1
First cylinder: <enter>
Using default value 1
Last cylinder, +cylinders or +size{K,M,G}: +2000M

Create the second partition:

Command (m for help): n
Command action
e   extended
p   primary partition (1-4)
p
Partition number (1-4): 2
First cylinder: <enter>
Last cylinder, +cylinders or +size{K,M,G}: <enter>

Set the partition type of the first partition to vfat/fat32

Command (m for help): t
Partition number (1-4): 1
Hex code (type L to list codes): b
Changed system type of partition 1 to b (W95 FAT32)

Set the partition type of the second partition to Linux

Command (m for help): t
Partition number (1-4): 2
Hex code (type L to list codes): 83

Set the first partition to active

Command (m for help): a
Partition number (1-4): 1

Write out the current partition table to the disk

Command (m for help): w

Format the partitions, substituting your drive for sda as neccessary

mkfs.vfat /dev/sda1
mkfs.ext3 -b 4096 -L casper-rw /dev/sda2

Mounting and Copying Files:

Next we need to mount the flash drive that we just made partitions on

mkdir /mnt/sda1
mount /dev/sda1 /mnt/sda1

Then we will use rsync to copy the files from the DVD to the flash drive.

cd /mnt/sda1
rsync -r /media/cdrom0/* .

Installing grub:

Now that we’ve copied all of the files over, we must now install a bootloader on the flash drive.

grub-install –no-floppy –root-directory=/mnt/sda1 /dev/sda

Persistent Changes:

Now that grub is installed, we are technically done, but I like to make some changes to the grub boot menu so that it picks persistent changes mode by default.

cd /mnt/sda1/boot/grub
nano menu.lst

You will need to change the default to 4.

Tweaks:

One thing I like to do is enable networking by default as it is normally disabled. To accomplish this, you need to boot from the actual flash drive and then run the command:

/usr/sbin/update-rc.d networking defaults

Closing:

BackTrack is a great resource for checking the security of your home network.  It really provides you with pretty much every tool to audit your home network. Now you will be able to take you flash drive and audit any network.

Update:

The public version of BackTrack R1 has been released and can be found here: http://www.backtrack-linux.org/downloads/