Partitioning criteria revision proposal

[Adam Williamson]

On Thu, 2012-10-11 at 07:49 -0400, Kamil Paral wrote:
> > current
> > -------
> > 
> > * The installer must be able to complete an installation using
> > automatic
> > partitioning to a validly-formatted disk with sufficient empty space,
> > using the empty space and installing a bootloader but leaving the
> > pre-existing partitions and data untouched
> > 
> > * The installer's custom partitioning mode must be capable of the
> > following:
> > ** Creating, destroying and assigning mount points to partitions of
> > any
> > specified size using most commonly-used filesystem types
> > ** Creating encrypted partitions
> > ** Rejecting obviously invalid operations without crashing
> > 
> > * The installer must be able to create and install to software,
> > hardware
> > or BIOS RAID-0, RAID-1 or RAID-5 partitions for anything except /boot
> > 
> > 
> > 
> > Here are my proposed changes.
> > 
> > proposed
> > --------
> > 
> > * The installer must be able to complete an installation to a
> > validly-formatted disk with sufficient empty space, using the empty
> > space and installing a bootloader but leaving the pre-existing
> > partitions and data untouched, without using the custom partitioning
> > mode
> 
> I don't like "custom partitioning" term. People might be confused
> whether "reclaiming space" is custom partitioning or not. Also, I feel
> that we try to enforce some design decisions here - we try to claim
> that there should an "easy mode" and an "advanced mode" and it should
> work like this and that... do we really want to enforce that? I would
> rather specify what needs to work, rather how.

I entirely agree with you in theory, I've said the same thing before,
but I think in practice it might be needed here. The understanding is
that we're not actually dictating design with the criteria, we're
reflecting current design. Just as we're changing the criteria now
because newUI came in - we didn't just go tell the anaconda team 'make
new UI look like old UI because that's what the criteria say' - if they
changed the design again, we'd change the criteria.

I'm not in love with it, but I think it may be necessary just to make it
really clear what the criteria *mean*. anaconda does have these two
workflows, and I'm not sure we can really state our requirements in a
way that doesn't acknowledge that design somehow.

> In this case we should probably replace "without using the custom
> partitioning mode" with a requirement that anaconda is able to
> automatically create a new working partition layout for you. That has
> the same intended meaning, but doesn't specify UI workflow. So
> something like this:
> 
> " The installer must be able to automatically create a functional
> partition layout using just the empty disk space if you provide it
> with a validly-formatted disk with sufficient empty space.
> Pre-existing partitions and data must remain untouched and the
> bootloader must be correctly installed. "

The probably with that is the custom partitioning contains an
'automatically create partitions in empty space for me' button now. So
if the 'guided partitioning' workflow was entirely broken but the
'custom partitioning' workflow worked, you could argue that this
criterion would be satisfied. Which I don't think is what we want.

> > 
> > * When there is not sufficient free space for installation, the
> > installer must allow the user to selectively remove existing
> > partitions
> > without using the custom partitioning mode
> 
> The easiest way here would be to append it to the previous criterion:
> 
> " The installer must be able to automatically create a functional
> partition layout using just the empty disk space if you provide it
> with a validly-formatted disk with sufficient empty space.
> Pre-existing partitions and data must remain untouched and the
> bootloader must be correctly installed. If there is not sufficient
> free space for installation, the installer must allow the user to
> selectively remove existing partitions."

That works too, but I was trying to keep the criteria short and clear.
This one would probably overflow in IRC.

> > 
> > * The installer's custom partitioning mode must be capable of the
> > following:
> > ** Creating and, optionally, encrypting partitions of any specified
> > size
> > using all offered device and filesystem types
> > ** Assigning mount points to newly-created partitions
> > ** Using an existing partition as the /home partition for the
> > installation without reformatting it
> > ** Deleting any existing partition
> > ** Rejecting obviously invalid operations without crashing
> > 
> 
> Let's delete "custom partitioning mode" and it's OK:
> 
> " The installer must be capable of the following:
> <no changes here>

See above...
-- 
Adam Williamson
Fedora QA Community Monkey
IRC: adamw | Twitter: AdamW_Fedora | identi.ca: adamwfedora
http://www.happyassassin.net