Why doesn't ubuntu 16.04 allow writing to a connected flash drive?

Question

linux

I connected a flash drive to the installed ubuntu 16.04. An image of the same ubunta was already recorded on it with a standard program for recording bootable flash drives. Why is it not writable? And this problem is not on one machine.

Answer 1

What is the standard program? If the .iso file was written using image writer or dd, then the file system on the flash drive is like on CDs, it cannot write.

Answer 2

A flash drive without write protection? (such a small switch on a flash drive)

Answer 3

A long time ago in a galaxy far, far away..... in Unetbootin there was a checkbox, when creating a bootable flash drive, "allow the system to save changes to disk", that is, in live mode (without installation), ubunta remembered the settings and installed packages. For this, all available space on the flash drive was marked. I think that the built-in utility does this by default. From that, nothing more fits on it. Try re-formatting the flash drive and create a bootable one with another program, for example, the same notorious Unetbootin, but write only the image, this will probably solve the problem.