I would clone my partition
/dev/sda1 on Ubuntu 14.04.
I've downloaded Clonezilla in order to clone this partition and be able to reinstall it later.
As recommended on the CloneZilla's website, I used Tuxboot to install a CloneZilla iso on my USB key.
I've started my PC from the USB key, it worked and I saw a GRUB-like menu that contains a list of boot modes.
The problem is the following, I can't boot in any mode, I have the following error:
overlayfs: missing 'workdir'
I have no idea about the problem it is the first time I try to clone a partition.