Successfully created Ubuntu 22.04 USB disk after following the tutorial at: How to Create a Full Install of Ubuntu 22.04 to USB Device Step by Step
To create full backup of the USB I am selecting drive to image backup option in Clonezilla ..the first, unformatted 1 MB partition i.e. sdf2 (labelled as BIOS in the image) is not cloned as filesystem is unknown.
If this partition is needed for proper booting of UEFI Ubuntu USB, then please suggest how to configure Clonezilla so that this partition is also cloned? Or any other method?