My clone image creations (image file) kept failing with the msg "unable to write to device" and further up on the screen (as Clonezilla displays logs of what is happening) I noticed "The volume group setting is not found". Great what does that mean?
The "The volume group setting is not found" error is thrown because there is a "lvm" flag (or in GParted it will display as "lvm2 pv") set for a partition AND there is no actual Volume Group setup in that partitions file system. Which then results in the misleading error msg from Clonezilla "unable to write to device".
Once you create the VG/LV on that partition OR remove the "lvm" partition flag, you no longer will receive these error message and will be able to write to your drive.