Ubuntu
ubuntu-release-upgrader package

  1. Bug #1509305
  2. Comment #15

Comment 15 for bug 1509305

Revision history for this message
Brian Murray (brian-murray) wrote : Re: new kernel removed after upgrade if linux meta package not installed

The way the release upgrade process works is that it downloads a tarball from the next release we can see this in the meta-release file.

Dist: wily
Name: Wily Werewolf
Version: 15.10
Date: Thu, 22 October 2015 15:10:00 UTC
Supported: 1
Description: This is the 15.10 release
Release-File: http://archive.ubuntu.com/ubuntu/dists/wily/Release
ReleaseNotes: http://archive.ubuntu.com/ubuntu/dists/wily-updates/main/dist-upgrader-all/current/ReleaseAnnouncement
ReleaseNotesHtml: http://archive.ubuntu.com/ubuntu/dists/wily-updates/main/dist-upgrader-all/current/ReleaseAnnouncement.html
UpgradeTool: http://archive.ubuntu.com/ubuntu/dists/wily-updates/main/dist-upgrader-all/current/wily.tar.gz
UpgradeToolSignature: http://archive.ubuntu.com/ubuntu/dists/wily-updates/main/dist-upgrader-all/current/wily.tar.gz.gpg

So when the upgrade from Vivid to Wily is performed, we download the version of ubuntu-release-upgrader from wily. Subsequently, the fix only needs to appear in the release to which the upgrade is being performed.

Having said that it's likely Vivid does need a fix for upgrades from Trusty, but this is currently untestable because of bug 1497688.