GNOME and protecting Sugar --

Bernie Innocenti bernie at
Tue Jun 15 20:17:45 EDT 2010

El Tue, 15-06-2010 a las 18:27 -0400, Martin Langhoff escribió:
> in Paraguay, how did you manage the situation with GNOME and
> protecting Sugar from obvious damage.
> Back then, the first apparent issue was that ~/Activities appeared
> right in the middle of the gnome file manager, and was way too
> tempting to mess with it (and messing with it would kill Sugar).
>  - How did you solve the problem? There was mention on the list of a
> ".hidden" file with hints to the file manager, did you use that?
> Something else?

During the last development cycle we lacked the time to lock-down GNOME
a little more and we're still paying the consequences :-(

>  - Were there any other problems? Solutions?

Indeed, some kids manage to do damage Sugar, with or without intention.
More frequently, they mess up the panel icons in ways that make it
difficult to restore functionality.

In one case, a kid managed to click "Disable Networking" in nm-applet
and then switch back to Sugar. Not "Disable Wireless", that would have
been easy! It took me one hour of debugging to figure that out.

Everyone, including teachers and teacher trainers, manages to fill up
the filesystem with large multimedia files downloaded from the Internet,
solowing down the system due to frequent jffs2 garbage collections.

In some cases, it's not the user's fault: various programs, including
Firefox and Browse, can hide up to 50MB of junk in dot-files. Clever
users managed to discover some of these locations and passed the word.

If a kid breaks the system in any non obvious way, the technicians will
just reflash it. Now we have a rudimentary UI to restore the journal
backup, but all work done in GNOME is lost.

> a large deployment is wondering about adding GNOME to the mix
> (including Orca is one of the reasons...), and how to manage the
> risk...

On the positive side, many children and teachers simply love GNOME. It
would no longer be possible for us to convince them to upgrade to a
version which removes it.

Perhaps unsurprisingly, a teacher told me that her younger son likes
Sugar, while the older uses GNOME.

To mitigate the problem:

 - lock down the panel:

 - add a "panic button" to olpc-configure which would bring up a
   text menu with various recovery functions, such as resetting
   GNOME configuration to its default and clearing temporary caches.

 - remove the desktop switcher icon from the Sugar control panel
   give the field technicians a secret shell command to restore it.
   This should prevent children who are too young to figure it out.

 - Hide the Activities. We can't really make them read-only or
   immutable because the updater runs as user olpc.

 - Also hide .sugar

A 100% robust GNOME desktop would require a complete redesign. The end
result might end up being very similar to Sugar! The only practical
advantage of GNOME over Sugar is its flexibility. If we lock it down too
much, it would become quite useless.

Rather than preventing breakage at all costs, which is rather hard, we
could spend some time to improve our backup/restore procedures to
minimize the chance of user data loss.

Tch and Jasg have been working with Esteban (Plan Ceibal) to cleanup and
enhance backups. I'll merge their patches over the next few days to give
them some exposure, even though we're still there are several
opportunities for enhancement.

   // Bernie Innocenti -
 \X/  Sugar Labs       -

More information about the Devel mailing list