Alguns dos meus servidores foram atualizados de 12.04 para 14.04 no início de 2015 (observe que é outubro de 2016) sem problemas. Atualizou dezenas de sistemas semelhantes anos atrás e, em geral, nunca tive um problema com isso.
Eu tenho um servidor que estou tentando fazer agora e está me dando o erro "sem novo lançamento encontrado".
Apenas curioso se estou perdendo algo ou se houve uma alteração no último ano ou mais no método de atualização. Você tem alguma ideia?
Obrigado,
-Ryan
sudo do-release-upgrade
Checking for a new Ubuntu release
No new release found
lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 12.04.5 LTS
Release: 12.04
Codename: precise
/etc/apt/source.list:
deb http://us.archive.ubuntu.com/ubuntu/ precise main restricted
deb-src http://us.archive.ubuntu.com/ubuntu/ precise main restricted
deb http://us.archive.ubuntu.com/ubuntu/ precise-updates main restricted
deb-src http://us.archive.ubuntu.com/ubuntu/ precise-updates main restricted
deb http://us.archive.ubuntu.com/ubuntu/ precise universe
deb-src http://us.archive.ubuntu.com/ubuntu/ precise universe
deb http://us.archive.ubuntu.com/ubuntu/ precise-updates universe
deb-src http://us.archive.ubuntu.com/ubuntu/ precise-updates universe
deb http://us.archive.ubuntu.com/ubuntu/ precise multiverse
deb-src http://us.archive.ubuntu.com/ubuntu/ precise multiverse
deb http://us.archive.ubuntu.com/ubuntu/ precise-updates multiverse
deb-src http://us.archive.ubuntu.com/ubuntu/ precise-updates multiverse
deb http://us.archive.ubuntu.com/ubuntu/ precise-backports main restricted universe multiverse
deb-src http://us.archive.ubuntu.com/ubuntu/ precise-backports main restricted universe multiverse
deb http://security.ubuntu.com/ubuntu precise-security main restricted
deb-src http://security.ubuntu.com/ubuntu precise-security main restricted
deb http://security.ubuntu.com/ubuntu precise-security universe
deb-src http://security.ubuntu.com/ubuntu precise-security universe
deb http://security.ubuntu.com/ubuntu precise-security multiverse
deb-src http://security.ubuntu.com/ubuntu precise-security multiverse
/ etc / update-manager / release-upgrades
# Default behavior for the release upgrader.
[DEFAULT]
# Default prompting behavior, valid options:
#
# never - Never check for a new release.
# normal - Check to see if a new release is available. If more than one new
# release is found, the release upgrader will attempt to upgrade to
# the release that immediately succeeds the currently-running
# release.
# lts - Check to see if a new LTS release is available. The upgrader
# will attempt to upgrade to the first LTS release available after
# the currently-running one. Note that this option should not be
# used if the currently-running release is not itself an LTS
# release, since in that case the upgrader won't be able to
# determine if a newer release is available.
Prompt=lts
Eu tive o mesmo problema, mas resolvi isso.
Por favor, certifique-se de fazer isso antes da atualização real.
sudo apt-get update
sudo apt-get upgrade
Resolva os problemas que você encontrar neste momento primeiro.
Então você pode encontrar "Nenhuma nova versão encontrada" quando você executar "sudo do-release-upgrade". Tente "sudo apt-get instalar update-manager" antes de "sudo do-release-upgrade". Isso resolveu meu problema.
Boa sorte!