Set bootable flag on USB drive
$ sudo fdisk /dev/sdb #/dev device needs to be a hard drive(sdb) not a partition(sdb1)
Command (m for help): a
Partition number (1-4): 1
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
$ sudo fdisk -l
<--- output omitted ----->
Disk /dev/sdb: 2002 MB, 2002747392 bytes
255 heads, 63 sectors/track, 243 cylinders, total 3911616 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000
Device Boot Start End Blocks Id System
/dev/sdb1 * 63 3911615 1955776+ c W95 FAT32 (LBA)
Format USB stick
sudo fdisk -l #find out your usb device
df
umount /dev/sdb1
mkfs.vfat /dev/sdb1 #create fat32
mkfs.ext3 /dev/sdb1 #create ext3
mkdosfs -F 32 -I /dev/sdb1 #format device to fat32
Copy .iso on USB stick
sudo dd if=image.iso of=/dev/sdb1
Mount .iso
sudo mkdir /mnt/isoimage
sudo mount -o loop -t iso9660 image.iso /mnt/isoimage/