It appears that your approach failed due to using the Ubuntu 14.04 ISO as the source.
Why not simply image the SSD after installing and applying your changes and apply that image to to your USB flash drive? Provided that your flash drive is of equal or larger size this is a snap. Even if it's not you can still prevail by shrinking filesystem(s) via
Creating an Img of of a customized system drive to USB:
- After installing, booting into your new system and configuring it as desired
open a terminal on your newly configured system and run
mount to insure which drive you will be imaging ( it will be mounted at / ). make a note of it.
- Choose a live Ubuntu media. The flavor doesn't matter much as we're going to mostly be working from the command line. Feel free to use the flavor you are most comfortable with. If you don't have one you can make one as described elsewhere on this site.
We will boot off of live media in order insure that the drive we are imaging is not mounted when we image it as we don't want changes to occur during the process. (If you have a dual boot system with 2 flavors of Ubuntu installed you can simply use the 2nd installation to image the first)
Use your BIOS boot selection menu (varies by manufacturer) selecting the live media to boot from.
Once at the live media menu choose “Try without installing”
3.Once the system comes up choose software sources and activate the universe repository as we are going to add a program to our live session.
Open a terminal and issue the command
sudo apt-get install dc3dd
follow the prompts and install the software as normal.
Once this is complete issue the command
sudo fdisk -l
Verify that the drive you wish to duplicate matches your note made previously. Also make note of the size of the drive and insure that the image will fit on it
4.Mount any internal or external media (other than the source drive) you have available to contain the image that has enough space to do so. (The image will be the exact size of the source drive)
Where you mount it is up to you but in the case of an external it will likely automount somewhere like /media/label, pay attention and make note of where your target media is mounted. From here on I will refer to this mount location as /mnt/target and you will substitute your target for mine.
5.Creating the image
Issue the command
dc3dd if=/dev/sdX of=/mnt/target/sdX.img Where sdX is the drive you made note of in step 1. Note
dc3dd will provide a running status of the image creation so you can see how far along it is. Once the image is complete check the size to insure that it will fit on your flash media. If so we can simply apply it to the flash media.
6.Applying the image
Plug in the target media and verify it's device name with either Disks in the GUI or
sudo fdisk -l at the CLI (terminal) Unmount it if it's automounted with either Disks in the GUI or via the
umount /dev/sdY command in the terminal where /dev/sdY is your flash media.
Now issue the command
dc3dd if=/mnt/target/sdX.img of=/dev/sdY where /dev/sdY is your flash media and /mnt/target/sdX.img is the image file we created in the previous step. All data on the chosen of= will be overwritten with the content of the image file. It is assumed that you are paying attention and you won't be asked if you are sure!
Once the process is complete you can issue the command
sync to insure any buffers in use are flushed, remove the flash media and boot your duplicated system on whatever system you want.