HOWTO Boot Linux from a USB 2GB Pen Drive - Curtin University

HOWTO Boot Linux from a USB 2GB Pen Drive
Author: Leigh Harrison
Date: 01.12.06
File: usb_2gb_howto.odt
Email: L.Harrison@curtin.edu.au
Tel: +61 8 9266 4727
HOWTO Boot Linux from a USB 2GB Pen Drive
Leigh Harrison, December 2006
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HOWTO Boot Linux from a USB 2GB Pen Drive
Table of Contents
1. Purpose.............................................................................................................................................3
2. Scope................................................................................................................................................3
3. Reference Documents.......................................................................................................................3
4. Glossary............................................................................................................................................3
4. Installation........................................................................................................................................4
4.1 Obtain Knoppix..........................................................................................................................4
4.2 Prepare the Pendrive..................................................................................................................4
4.3 Partition the Drive......................................................................................................................4
4.4 Install the syslinux Bootloader..................................................................................................5
4.5 Mount the New Partition............................................................................................................5
4.6 Copy Contents of Knoppix Boot Directory...............................................................................5
4.7 Copy the Rest of the Knoppix CD.............................................................................................5
4.8 Ready to Boot!...........................................................................................................................5
4.9 Make the USB Pendrive Read/Write.........................................................................................6
4.10 Installing Binaries....................................................................................................................6
4.11 Further Work............................................................................................................................6
4.11.1 mkdiskimage Settings......................................................................................................6
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HOWTO Boot Linux from a USB 2GB Pen Drive
1. Purpose
This document describes the method of installing a bootable Linux operating system on a USB pen
drive.
2. Scope
This method applies to a 2GB USB pen drive but smaller memory sizes should still work with this
methodology. The Linux OS used for the installation was Knoppix 5.01 Live CD.
3. Reference Documents
Doc No. Title Author Contact
1. USB Pendrives and Distributions for Them – Linux Journal, June
2006, pp 86-88
Juan Marecelo
Rodriguez
www.linuxjournal.com
2. Bootable USB Key www.knoppix.net/wiki/Bootable_US
B_Key
3. Linux in Nutshell, 2nd Ed., Oreilly Ellen Siever www.oreilly.com
4. Glossary
Term Meaning
Knoppix A Linux OS distribution produced by Klaus
Knopper, based on Debian Linux.
See www.knopper.net/knoppix/index-en.html
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HOWTO Boot Linux from a USB 2GB Pen Drive
4. Installation
4.1 Obtain Knoppix
Download a copy of Knoppix 5.01 from http://www.knopper.net/knoppix-mirrors/index-en.html .
Burn a CD from the iso image and check that it boots from a PC. you may have to change the BIOS
boot sequence for this to happen.
4.2 Prepare the Pendrive
Insert the 2GB USB pen drive as soon a the boot: message appears in the GRUB bootloader. This
ensures that Knoppix will find it using autodetection.
The “cheatcodes 1 ” are passed at the boot: message to set various parameters and start services. Do
not use the toram cheatcode as this does not include the /boot directory, which is required by the
pendrive.
Login as root:
su
Followed by RETURN.
Check the drive letter of the USB pendrive; it should be typically /dev/sda or similar.
Try:
dmesg grep ­i scsi
or
dmesg grep ­i usb
or
cat /proc/partitions
Next, erase the USB pendrive. A word of caution: Make sure that you have correctly identified the
device correctly. The next bit can wreak havoc with your hard-drive if you pick /dev/hda instead
of /dev/sda, etc.
Erase the pendrive (assuming your device is /dev/sda):
dd if=/dev/zero of=/dev/sda
This took about ten minutes on my Astone 2GB pendrive and a “no space left on device” should
appear when it's done.
4.3 Partition the Drive
The USB pendrive can now be partitioned with the following command:
mkdiskimage /dev/sda 0 256 63
This also take some time to complete. The mkdiskimage command creates the master boot record,
partition table and then partitions and formats the drive as a FAT16 partition. It sets up the image as
a USB-HDD which most modern BIOS can handle. The reference document used the -4 option
which set up the image as USB-ZIP. This is more universal than perhaps USB-HDD but it limits the
1 http://www.knoppix.net/wiki/Cheat_Codes
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HOWTO Boot Linux from a USB 2GB Pen Drive
maximum image size to 1GB and it won't work on a 2GB device!
KDE may start a pop-window when the new partition is recognized. Simply close it.
4.4 Install the syslinux Bootloader
Install the syslinux bootloader on the new USB pendrive partition:
syslinux ­s /dev/sda1
A new file, ldlinux.sys is also installed.
4.5 Mount the New Partition
Mount the partition:
mount /media/sda1
Knoppix should have found the new partition by auto-detection and set up an entry in fstab.
/dev/sda1 should be mounted at /media/sda1 .
Check that only on file is present on the USB partition (ldlinux.sys).
cd /media/sda1
ls
4.6 Copy Contents of Knoppix Boot Directory
Copy the contents of the Knoppix boot directory onto the USB partition.
cp ­av /cdrom/boot/isolinux/* .
mv isolinux.cfg syslinux.cfg
rm ­f isolinux.bin
Ignore “failed to preserve ownership” error messages. These are due to the FAT file system which
doesn't support file ownership.
The reasons behind this sequence of commands are described in detail in 3.1, Reference No. 2.
The Knoppix CD's boot directory is copied first to get it as near to the beginning of the drive as
possible.
4.7 Copy the Rest of the Knoppix CD
Check that you are still in the /media/sda1 directory and copy the remaining items.
cp ­av /cdrom/* .
rm ­rf ./boot
This takes some time to complete. The duplicate copy of the ./boot directory is removed.
4.8 Ready to Boot!
Unmount the USB pendrive.
sync
cd /
umount /media/sda1
sync
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HOWTO Boot Linux from a USB 2GB Pen Drive
Shutdown Knoppix and reboot the PC. Change the BIOS boot sequence so it boots from the USB
pendrive and save the settings. Allow the USB drive to boot up.
4.9 Make the USB Pendrive Read/Write
The default configuration for the Knoppix image is read only. It appears as a CD-ROM. However, it
can be made read/write as follows:
mount ­o remount,rw /cdrom
mount ­­bind cdrom /media/sda1
The /home/knoppix directory should now be made persistent so that data and settings can be
saved. Under the Penguin menu select Configure, Create Persistent. Select a useful size but don't
use the all of the remaining of the space available on the pen drive, to allow for quick file copying
etc. I had about 1.2 GB left and chose 684 kB but this is optional. The persistent home directory is
reformatted as ext2. Reboot and select the persistent home directory during boot-up. All settings
will be saved and files can be now stored in the /home/knoppix directory.
4.10 Installing Binaries
Binaries can be installed by copying *.tar.gz source files onto the pen drive and compiling in the
usual way. Copy or move the source files from the root directory to the /home/knoppix directory.
The source files can be untarred and installed as root from there in the usual way. Copy the binaries
as the user knoppix 2 from the /usr/bin or /usr/local/bin (or wherever it's placed during the
installation) to the /home/knoppix directory.
4.11 Further Work
4.11.1 mkdiskimage Settings
I used the following settings which worked without any problems.
Command c h s
mkdiskimage /dev/sda1 0 256 63
However, it is suggested in reference 2 that 255 heads be used “as it's slightly more compatible”.
For pen drives which are greater than 2 GB it's suggested that FAT32 is used rather than FAT16.
This requires the use of the -F option as follows:
mkdiskimage ­F /dev/sda1 0 256 63
2 If you do the copy as root you will have to change owner and group to knoppix.
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