First, we create 2 partitions on the USB stick that is let's say 16GB. first partition is let's say only 1GB and the second partition is the rest of what is available. after we "w" write the changes, the USB now has 2 partitions. 1 is 1GB 1 is more than 14GB so , we have... sdb1 and sdb2 now. now we need to turn these partitions into filesystems some say i should run these commands after those procedures. mkfs.vfat -F 32 /dev/sdb1 mkfs.ext3 /dev/sdb2 but some web pages recommend using: mkfs.vfat -n BOOT /dev/sdb1 mkfs.ext2 -m 0 -b 4096 -L DATA /dev/sdb2 which is it? so let's say the DVDs are called: CentOS-6.4-x86_64-bin-DVD1.iso CentOS-6.4-x86_64-bin-DVD2.iso so we make a directory: mkdir -p /mnt/dvd1 and then mount it: mount -o loop CentOS-6.4-x86_64-bin-DVD1.iso /mnt/dvd1 and i suppose we don't make a directory for dvd2 and we don't have to mount it ? at this point i do not know what should be done. but i think this step might be next: we make the USB bootable by finding the file named mbr.bin and then moving it to there via these commnad. dd conv=notrunc bs=440 count=1 if=/usr/lib/syslinux/mbr.bin of=/dev/sdb parted /dev/sdb set 1 boot on in other words we are "dd-ing it to 'sdb' not sdb1' or 'sdb2'. and then we use parted to set the boot to on for sdb so far everything looks good? here is the confusing parts.. how exactly do i move these iso files to the usb drive? EVERYTHING BELOW IS A GUESS. so at this point i should copy the folder /mnt/dvd1/isolinux to usb's sdb1 or sdb2 ? rename it to syslinux ? and then inside this syslinux folder there will be a file called... isolinux.cfg ? which should be renamed to syslinux.cfg ? and then copy the contents of /mnt/dvd1/images/* to USB's sdb2 ? but i think i am also suppose to copy and paste the both CentOS-6.4-x86_64-bin-DVD1.iso CentOS-6.4-x86_64-bin-DVD2.iso somewhere into this USB's sdb2 partition, correct ? almost like a drag and drop kind of a thing? or do they go into any folders ? centos' own web site has some instructions but those instructions do not work. http://wiki.centos.org/HowTos/InstallFromUSBkey i once got this working but things got ruined, i have to do it again and this time take notes.