force local repository on upgrade

[dread22]

I want to upgrade from 9.04 to 9.10 but I have a much faster connection to the local repository than the official ones and my downloads are not counted.

Is there a way to force the use of the local mirror for the distribution upgrade instead of the official mirror.

[sebastianabate]

Yes, you can. This is extracted from this bug

The way it works is that you drop a file in /etc/update-manager/release-upgrades.d/
with the extension .cfg (e.g. /etc/update-manager/release-upgrades.d/my-config.cfg) that contains:
[Sources]
AllowThirdParty=yes

[sedawk]

Thankx, your solution is the easiest and best solution I found on
the internet!

In more detail, here is what I did to install from in "apt-mirror" mirror
on my usb-stick:

1) I did a final apt-get update and apt-get upgrade with the old distro
and the old sources.list. I checked that update-manager offers the
button for installing the new distro.
2) Copied sources.list to sources.list.net and created a new sources.list

deb file:/media/<usb_mirror>/ubuntu precise main restricted
deb file:/media/<usb_mirror>/ubuntu precise-updates main restricted

3) Tried apt-get update to see if the new sources.list works
4) created /etc/update-manager/release-upgrades.d/my_mirror.cfg
according to your posting
5) Start update-manager (-d)
6) Stage "Getting new packages" took some time (checking packages?), but
did not download anything
7) Installation started and is still running now.
(Installation from my USB stick is estimated to take 1 hour)

Post) Update entries in sources.list.net manually to new distro and
copy it to sources.list again ...

Thankx