To cope with unexpected crashes, I decided to dedicate a 2GB usb device for storing ubuntu 16.04 live usb, so that I can boot from the live usb and fix some boot issues or Grub related issues.
I made another bootable disk burned with clonezilla so that I can recover from a previously backed up image if the system really got messed up from my crazy experiments, in a way that is not fixable using live usb( Or if I want to use it in another machine to fix boot issues or clone my disk image in a new machine)
Now, the question is, Can I use a single usb to store both clonezilla and the live ubuntu 16.04 image ? May be using different partitions on the same usb?