I'm running Ubuntu 13.04, and would like to upgrade to 14.04.
Entering the following commands gives me output indicating that it cannot be done.
$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 13.04
Release: 13.04
Codename: raring
$ sudo do-release-upgrade
Checking for a new Ubuntu release
No new release found
How can this be done?
(I have the ISO file for 14.04 too, if that makes a difference)
Update:
As per the sugestion below, I tried this, to no avail?
$ sudo do-release-upgrade -d
Checking for a new Ubuntu release
No new release found
Update:
Further investigation revealed that updates were not working too.
$ sudo apt-get update
# truncated
E: Some index files failed to download. They have been ignored, or old ones used instead.
Are there any software sources that still host raring (13.04)?
Update:
Editing the software sources to point to old-releases.ubuntu.com worked, enabling
sudo apt-get update && sudo apt-get dist-upgrade
To run as expected. However,
sudo do-release-upgrade -d
still yields the same result:
Checking for a new Ubuntu release
No new release found