I'm running an upgrade from Maverick to Natty from a mounted 'alternate' ISO, but it's current status is "Fetching file 1444 of 1703 at 55.1 kB/s". I'm pretty sure it's trying to use the network for the "Getting new packages" phase. How can I make sure it uses only the ISO, and not the network? Disconnecting the network (or keeping it disconnected the entire time) just results in stalling (waiting, not freezing) during the "Getting new packages" phase.
I've followed the instructions on the Ubuntu Wiki for upgrading using the Alternate CD ISO mounted as a drive. Also, I selected "No" to the question about updating packages during the upgrade.
If this is a bug, please give a link with the bug number or tell me that I should file a bug.