setup-storage and preserving partitions

[Jeffrey Stolte]

On Fri, Mar 26, 2010 at 05:01:00PM +0100, Michael Tautschnig wrote:
> 
> I think I never thought of such a use case :-) - whatever the reasons
> may be that you are so keen on preserving sizes, as apparently
> nobody requested "preserve the size only" before, that feature is
> indeed missing.  For partitions 6 and 7 you can either say preserve6,
> preserve7 or just put some arbitrary size in there.  For the others,
> however, we'll need a new option :-(
>
> For the moment, the only workaround I can see is a hook that does
> the formatting after setup-storage has run, but that shall not be
> the long-term solution.
>
> The easiest approach would be some additional option preserve_size,
> but I'm not sure whether this is the best thing to do.  Could you
> maybe give me a brief account of your rationale behind preserving
> the size only to gain a better understanding?
>
> Thanks a lot,
> Michael

Thank you for your quick reply to my question.  I'm somewhat relieved to
know that I wasn't missing some obvious option. :)  As for our rationale
behind preserving the partition sizes, I think we've always felt that
there was much less risk of data loss if we modified the existing
disk as little as possible.  Also, many times our users have filled
their /home and /d1 partitions to near capacity, so there is little
disk space left for re-sizing.  We also just like knowing that most
of our machines (300-400) have the exact same size system partitions.
(This is important for estimating backup capacity, etc.)

(I should mention that one of our main uses of FAI is to upgrade
machines from one Debian release to the next.  However, rather than do
an in-place upgrade, we do a fresh install of the new release while
preserving the existing partition sizes on the disk.)

I hope this makes some sense.  If no one else has asked for this
capability, though, maybe we need to reconsider our practice of
preserving partition sizes.  I don't want you to have to add an option
that no one else uses or that is not considered to be a "best practice".
Let me know if you need any additional information.  Thanks.

Jeff