I'm using rescue disk image to upgrade my system.  But there is a confusion
about stage2.img.  It seems that the CD contains it, but it is tricky to get to it.

When I'm asked, what media should be used, the answer "local CD/DVD" is not
accepted, because the CD is not an install media.

So I have to choose HTTP, configure the network interface and specify the http URL.

Then the installer discoveres that there is a media in the drive and asks me if
I'd like to check its checksum.

If I answer "Skip", then stage2.img is downloaded from the net, which takes some
time.

But if I answer "Go on, check my media", then the installer complains that there
is not checksum on the disk, _but_ it then uses the media and copies stage2.img
to my hard drive.

Isn't that all weird?

I admit I'm confused, but it may not be totally my fault...