olpc-update and deletion of old images

[Martin Langhoff]

On Thu, Sep 9, 2010 at 8:26 PM, Daniel Drake <dsd at laptop.org> wrote:
> On 9 September 2010 18:01, Martin Langhoff <martin.langhoff at gmail.com> wrote:
>> Can we do it in the bg with a very low-pri process? We'd have to mark
>> the "pristine" as "in process of deletion" if the deletion is stopped
>> we continue the job next round.
>
> It's an option, but I'm thinking that deleting the whole thing might
> be really quick. And waiting to free up the space before first boot of
> the new version is maybe a good idea, just in case the update process
> used very nearly all of the disk space.

Sounds reasonable. If it takes some time, we may need a spinner ("I'm
doing something, be patient").

Related: now that you mention low-disk-space, one thing that we
haven't sorted out is low-disk-space clients in the face of
olpc-update.

>> I am a bit hazy as to what happens to the non-pristine-tree of that
>> old version (holding any changed files on top of that old pristine).
>> Can we delete it sanely too?
>
> The run tree? Yes.
> There is already code for purging old versions (i.e. the "3rd
> version"). The deletion process would be the same, but would be
> applied to the "2nd version" as well.

Just gave olpc-boot-prepivot.sh a quick read and can't spot the
deletion you're talking about. Other things are being deleted but it's
not clear where this is handled.

It's all a good idea, my concern is that we _must_ handle power-loss
during the deletion elegantly...

cheers,



m
-- 
 martin.langhoff at gmail.com
 martin at laptop.org -- School Server Architect
 - ask interesting questions
 - don't get distracted with shiny stuff  - working code first
 - http://wiki.laptop.org/go/User:Martinlanghoff