video on demandLinux Create A Bootable USB Pen
by NIXCRAFT on MARCH 11, 2010 · 15 COMMENTS· last updated at MARCH 11, 2010
How do I create a bootable USB pen drive to start my CentOS / Fedora Linux? How do I create a bootable USB flash pen for installation of Linux, and for creation of rescue and other special-purpose boot disks using command line options?
You need to format your USP pen device as Win FAT32. Once formatted type the following commands to make it bootable.
Our Device Names
USB Pen Device Name : /dev/sdb1
DVD Mount : /media/cdrom0
USB Mount Point : /media/usb
USB File System : Win FAT32
ISO or DVD Image : Fedora / CentOS / RHEL
WARNING! These examples may crash your computer or result in data loss if not executed properly. You must understand device names, file systems and required to use fdisk partition table manipulator for Linux. This howto intended to simplify first-time installation of Linux, and for creation of rescue and other special-purpose boot disks.
To find information about your devices and current partitions run:
# dmesg | less
# dmesg | egrep -i 'cd|dvd'
# fdisk -l
Use the first command to identify the USB device name.
Mount CD/DVD ISO or DVD ITSELF
Type the following command to mount Fedora 12 iso image:
# mount Fedora-12-x86_64-netinst.iso -o loop /media/cdrom0/
# DVD=/media/cdrom0
# ls -l $DVD
Sample outputs:
total 6
dr-xr-xr-x 3 root root 2048 2009-11-09 05:37 EFI
drwxr-sr-x 3 root 499 2048 2009-11-09 05:37 images
drwxr-sr-x 2 root 499 2048 2009-11-09 05:36 isolinux
You need to use files stored in isolinux directory to create a bootable usb pen.
Format Usb
Create the fdisk partition:
# fdisk /dev/sdb
You need to create only 1 partition. Next format the partition:
# USB=/media/usb
# mkdosfs /dev/sdb1
Finally mount the partition:
# mkdir -p /media/usb
# mount /dev/sdb1 /media/usb
# USB=/media/usb
Copy Required Files
Type the following commands:
# cp -av $DVD/isolinux/* $USB
# cd $USB
# rm isolinux.bin boot.cat TRANS.TBL
# mv isolinux.cfg syslinux.cfg
Also copy the installer's initial RAM disk $DVD/images/pxeboot/initrd.img (for CentOS / RHEL Linux use $DVD/RedHat/images/pxeboot/initrd.img file) CD/DVD onto the usb drive:
# cp -v $DVD/images/pxeboot/initrd.img $USB
Unmount the USB drive
# umount /dev/sdb1
Make the USB Bootable
Type the following command to make the USB drive bootable
# syslinux /dev/sdb1
# mount /dev/sdb1 $USB
syslinux is a boot loader for the Linux operating system which operates off an MS-DOS/Windows FAT filesystem.
Install Grub
Type the following command to install GRUB on the USB device:
# grub-install --root-directory=$USB /dev/sdb
Create grub.conf:
# cd $USB
# mkdir -p boot/grub
Edit the grub.conf file
default=0
timeout=5
root (hd1,0)
title Fedora Linux
kernel /vmlinuz
initrd /initrd.img
Finally, unmount the USB pen drive, enter:
# umount /dev/sdb1