[Fedora-packaging] Systemd guidelines architectural decisions to be made

[Tom Callaway]

On 03/02/2011 06:11 PM, Toshio Kuratomi wrote:
> = Migration of user customization =
> 
> A lot of the other discussion in the FPC ticket right now is how to migrate
> information about what services are started.  This includes what runlevels
> to migrate and also which commands to use to perform the migrations.  I'll
> list the options that I can think of in a bit but I think the basic question
> is: do we want the user's system settings to just work when they do an
> upgrade or do we want them to start over with our defaults, redoing any of
> their customizations?

Okay, on this specific topic, I think there are three scenarios:

1) Users who do a fresh install.
   They will get an experience with systemd where fewer services start
   on boot than used to start on boot in Fedora 14.

2) Users have customized their runlevel settings, and then upgrade.

3) Users who have not customized their runlevel settings, and then upgrade.

The problem is that it is not possible to have scriptlets automatically
handle #2 (by migrating the customized settings into systemd) without
also affecting the experience of #3, when in an ideal universe, their
experience should be identical to #1.

I think the best compromise is to record the system runlevel state
during upgrade and not attempt to migrate settings. Document where the
state is recorded, and ideally, provide a tool to easily restore the
configuration into systemd, should the user wish it.

In talking with Toshio, he leans towards ensuring that #2 has a clean
experience as being more important, hence runlevel migration (this
affects #3).

What do other people think here?

~tom

==
Fedora Project