1. Attach the USB device to the Dom0 and run ‘dmesg’ to see if the device attached
2. Run ‘fdisk -l’ to see if the drive is partitioned the way you want it
3. For instance:
   [root@example ~]# fdisk -l /dev/sdc
   Disk /dev/sdc: 1000.2 GB, 1000204886016 bytes
   255 heads, 63 sectors/track, 121601 cylinders
   Units = cylinders of 16065 * 512 = 8225280 bytes
   Device Boot Start End Blocks Id System
   dev/sdc1 1 121601 976760001 8e Linux LVM
4. Now find a drive letter that is not being used on the DomU, in this instance we’ll use /dev/sde
5. To attach the USB device to the DomU run the following command
   • xm block-attach exampledomu phy:/dev/sdc sde w
6. You should now see the device on the DomU, run either ‘dmesg’ or ‘fdisk -l’ to verify
7. Mount the device as normal
   • mount /dev/sde1 /mnt/usb

Unmounting the device

1. You first need to get the device id number from the block list. Do this by running:
   • xm block-list exampledomu
2. This will return:
   Vdev BE handle state evt-ch ring-ref BE-path
   51712 0 0 4 9 8 /local/domain/0/backend/tap/23/51712
   2176 0 0 4 10 1338 /local/domain/0/backend/vbd/23/2176
3. The number you need to use to remove the device is 2176
4. Unmount the USB device from the DomU
   • umount /mnt/usb
5. Now on the Dom0 run:
6. xm block-detach exampledomu 2176
7. You may now remove the USB device