Re: Filesystem Hierarchy Standard 2.0 (fwd)

[Fabrizio Polacco <fpolacco@icenet.fi>]

Ian Jackson wrote:
> 
> I am here, honest.  
>
> [... symlinks work ...]
>

a)

> The best first thing to do is probably to make a version of base-files
> that has links from the _new_ names to the _old_ ones, once we decide
> what things we're going to change and how.
> 
> Then packages can start containing the new layout provided that they
> say `Pre-Depends: base-files (>= whatever)'.  dpkg will then install
> the stuff in the old locations.

b)

> When most of our packages are converted we can release a version of
> base-files which contains the opposite situation: the new directories
> and old links.  That will make newly-installed systems have the new
> layout and old systems have the old, and both old and new packages
> will work on either.

c)

> Later we can have a version of base-files whose postinst switches the
> directories and links around.
> This script has to be written with some care, [...]

d)

> In the far future we can remove the compatibility links from
> base-files.  This has to be considered carefully, because after those
> links are gone installing an old package will make `duplicate'
> instances of the moved directories.

Very nice: this seems far simpler than my proposal.

But why we should do it in three stages?
We could join c) with a) and have b) on the base-disks from the first
time.

So when most of our packages (if not all) will be updated to use the new
names, then d) will simply need a check in the local dpkg database to
see if there are files installed using the old names, and if not, remove
the links. If this is done by an on-purpose non-essential package, the
user will decide if and when do the removal, or even leave the symlinks
there forever.

So:
a)
The first thing to do is probably to make a version of base-files that
creates the new hierarchies and, in the postinst, moves the files
existing from the old to the new location [same problems as c) here, not
less, no more].

b)
Then packages can start containing the new layout provided that they say
`Pre-Depends: base-files (>= whatever)'.  dpkg will then install the
stuff in the new locations, as well as the old stuff.
When most of our packages are converted we ... need to do nothing.

c)
already done in a)

d)
In the far future we can remove the compatibility links from
base-files.  This has to be considered carefully, because after those
links are gone installing an old package will make `duplicate' instances
of the moved directories.
This will be a user's decision, anyway not worse then new installed
system in which the symlinks will never be created.



fabrizio
-- 
P.S.: To avoid mailing this only to you or to both you and the list I
had to do group reply, remove your address from the To: header, copy the
list address from the CC: to the To: header, remove it from the Cc:
Is this worth? Isn't better if you add a Reply-To: on your messages, so
replies got the way you prefere on the first place?
-- 
| fpolacco@icenet.fi    fpolacco@debian.org    fpolacco@pluto.linux.it
| Pluto Leader - Debian Developer & Happy Debian 1.3.1 User - vi-holic
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> Just because Red Hat do it doesn't mean it's a good idea. [Ian J.]