There are several answers on how to change hostname of Ubuntu, and all of them propose to do "the same changes" to
/etc/hosts. "The same" stands for "the same as in
/etc/hostanme". But unfotunately, these files have completely different formats, and they can't be changed in "same" manner.
So, the question is: what to write in
hosts to have hostname
and some IPv6 stuff which I don't understand.
So, should I replace