Hello,

First I want to thank you all for having a very informative and helpful forum. Now a summary of what I am doing and where I am trying to get with it. Summary: I am attempting to capture an image / file which contains the entire contents of a flash drive. I then want to write those contents to another flash drive, with the ultimate goal being writing to multiple flash drives at once. Details as follows:

A. Capture the image as a single file

1. Insert a drive that functions correctly and contains the image.
2. Find out what drives are present on the system
3. Open the terminal and run

sudo fdisk -l

4. Check out the sizes and the mount points to determine which
drives are USB drives, and which drive is the system hard drive.

Note: the USB drives should be 60 GB or less, and generally the first
usb drive in the system would be /dev/sdb

5. Given /dev/sdb is the drive I want to make into a file, I run the following command:

sudo dd if=/dev/sdb of=~/Usb_Image

This works fine. The file Usb_Image contains a copy of the data that was on the flash drive.


B. Write the file to a blank USB drive

1. Insert a blank 64 gb USB drive.
2. Find out what drives are present on the system
3. Open the terminal and run

sudo fdisk -l

4. Check out the sizes and the mount points to determine which
drives are USB drives, and which drive is the system hard drive.

Note: the USB drives should be 60 GB or less, and generally the first
usb drive in the system would be /dev/sdb

5. To copy the image data to the flash drive, run the following command:

sudo dd if=~/Usb_Image of=/dev/sdb

This also works fine. I end up with a bootable drive that is an exact copy of the original source drive.

And here is where I get lost... what I would like to to do is something like:

sudo dd if=~/Usb_Image | of=/dev/sdb | of=/dev/sdc | of=/dev/sdd

My goal is to copy the Usb_Image to multiple USB devices at once. I know the speed will be split among them as that is the way the USB hardware works. I have tried various commands found using Google, but so far no success. Consensus seems to be the tee command would be the way to go but I haven't been able to get the syntax to work. I am running Ubuntu 16.

I also tried running two terminal windows at the same time. One with

sudo dd if=~/Usb_Image of=/dev/sdb

and one with

sudo dd if=~/Usb_Image.drive of=/dev/sdc

Note that both Usb_Image and Usb_Image.drive are separate files but contain exactly the same data.

After both of the above commands completed , the usb at sdb had created correctly, while the usb at sdc only had 800 some MB on it... the Usb_Image file is almost 30 gb.

Thanks for your help.