Linux USB

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

df -h                              #find your usb device
lsblk                              #another way to find your device
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 to make bootable

This works only with hybrid ISOs images. The resulting USB stick will act exactly like a liveCD/DVD. of= (output file) value needs to be a hard drive (eg. sdb) not a partition (eg. sdb1).

sudo umount /dev/sdb
sudo dd if=image.iso of=/dev/sdb
sync

Convert .iso to hybrid image

Starting in version 3.72, ISOLINUX supports a "hybrid mode" which can be booted from either CD-ROM or from a device which BIOS considers a hard disk or ZIP disk, e.g. a USB key or similar. To enable this mode, the .iso image needs to be postprecessed with this utility. Hybrid images are special as in addition to the normal CD-based ISO9660 filesystem, they also contain a valid-looking DOS-style partition table. Note that old .iso images prior the supported version will not work.

isohybrid image.iso

This will append necessary information to the image file therefore the check-sum will change.

Mount .iso

sudo mkdir /mnt/isoimage
sudo mount -o loop -t iso9660 image.iso /mnt/isoimage/

Resources

• Isohybrid Wiki