Release upgrade an unsupported version of ubuntu
If you want to do a release upgrade with an unsupported version
of ubuntu, it seems to be quite straight forward, but nonetheless,
you run into a couple of difficulties, because the sources are
moved from archive.ubuntu.com
to
old-releases.ubuntu.com
which results in not finding
these if you want to do a release-upgrade.
What did the trick for me was to manually set the IP-Adress of
the server old-releases.ubuntu.com
in the
/etc/hosts
file for
archive.ubuntu.com
and
security.ubuntu.com.
All other suggestions like changing the url in the
/etc/apt/sources.list
and modifying the
/etc/update-manager/meta-release
file didn't
work, because i.e. of wrong checksums and in the end it always
tried to contact archive.ubuntu.com
for an updated
version of the packages.