The upgrade story

[Chris Murphy]

On Sep 11, 2014, at 2:20 PM, Rahul Sundaram <metherid at gmail.com> wrote:

> Hi
> 
> What is the plan for supporting upgrades from one release to another?  fedup still doesn't have a GUI and GNOME Software doesn't seem to have any integration for prompting users to perform the upgrade when a new release is available.

Short(er) version:
Seems a bit late for a GUI app if there isn't one already in progress. Is it correct that fedup will convert F20 to F21:Workstation only? And that F21:Server and Cloud will require clean installs? 

Gnome Software's updates, and fedup upgrades both leverage systemd "offline system updates" so it's possible there could be one "Upgrade to Fedora 21" option in Software. The caveat there is, it's a bit of a leap of faith. The user doesn't get an obvious "next step" until they restart and see the "fedup" option in the GRUB menu: assuming they haven't changed their GRUB behavior from our default, and haven't hidden the menu! Here they can continue to boot Fedora 20 by choosing the previous kernel, or choose the Fedora 21 Upgrade (fedup) option to get an upgrade.

We should have some consensus on whether the grub menu default should be Fedora 20 (do not do the upgrade by default), or the Fedora 21 Upgrade (fedup) option. Or maybe we modify grub.cfg to change the grub menu timeout so it hangs out a bit longer than usual; and reset it as part of a successful fedup upgrade.

Extra info:

Neither Workstation PRD nor Tech Spec provides very clear guidance. The PRD only mentions "upgrades" and the Tech Spec only mentions "updates".

The vernacular I'm familiar with: updates are minor version bug and security fixes, maybe some new features but maintaining API/ABI compatibility. Upgrades are major version changes (pretty much every binary on the system is going to be replaced), e.g. Fedora 20 to Fedora 21 is an upgrade.


Workstation Technical Spec on "updates"
http://fedoraproject.org/wiki/Workstation/Technical_Specification#Software_updates

-  "gnome-software will use PackageKit with the hawkey backend to obtain and install software updates for packaged applications and the OS itself. The recommendation for applications is to use the PackageKit APIs to interact with the underlying packaging system."

The Tech Spec probably should address "upgrades" specifically.

Workstation PRD on "upgrades"
http://fedoraproject.org/wiki/Workstation/Workstation_PRD

- "should give a result that is the same as an original install" (this is really hard to do; but I think it's a good goal and principle to have)
- "we want to offer an easy way for users to roll-back such upgrades" (we don't have this for either updates or upgrades right now for Workstation, as it depends on things we aren't using by default: ostree, LVM thinp snapshot, or Btrfs snapshots)



Chris Murphy