How to Make a usb Boot disk for Centos/RHEL from ISO File

You may need to install the following toll in your desktop,

# aptitude install  syslinux

Now download and ISO from Centos Mirror and convert the ISO to Hybrid ISO as follows,

# wget -c http://centos.excellmedia.net/6.4/isos/x86_64/CentOS-6.4-x86_64-minimal.iso
# isohybrid CentOS-6.4-x86_64-minimal.iso

Now plug your usb drive and format it using vfat

# umount /dev/sdc1
# mkfs.vfat /dev/sdc1

Now copy the ISO image using the following command ,

# dd if=CentOS-6.4-x86_64-minimal.iso of=/dev/sdc1

You may see a result like as follows,

root@myhome:/home# mkfs.vfat /dev/sdc1
mkfs.vfat 3.0.12 (29 Oct 2011)
root@myhome:/home# dd if=CentOS-6.4-x86_64-minimal.iso of=/dev/sdc1
702464+0 records in
702464+0 records out
359661568 bytes (360 MB) copied, 314.59 s, 1.1 MB/s

Now you can reboot your computer using this pen drive and install centos.