Re: partman, growlight, discoverable partitions, and fun

[Adam Borowski <kilobyte@angband.pl>]

On Sun, Sep 26, 2021 at 01:41:18AM -0400, nick black wrote:
> Marco d'Itri left as an exercise for the reader:
> > And the preseeding syntax is as powerful as it is inconvenient.

> > Implementing support for more partition formats, if missing, should be 
> > rather easy.
> > But which ones do we need for architectures which are not actually dead?
> 
> So, as I responded to Adrian [0], the only missing partition
> types appear to be amiga, atari, and sun. Adding them ought be
> simple enough, though I'd need testers with the hardware, or
> access to the hardware.

I'd start with asking porters of m68k and sparc64 whether today's systems
even run anything but Linux.  I think there's little point in keeping compat
with 80s' OSes.

At a risk of drawing ire of m68k/sparc64 folks, I'd also suggest not putting
your tuits there until this millenium's hardware is covered well.

> My biggest worry personally (aside from the realpolitik of
> getting this change through) regards the automated partitioning
> language available through the preseed system. Trying to emulate
> this bug-for-bug is a non-starter, I think, both from a
> technical and quality-of-life standpoint. If the emulation can't
> be perfectly accurate, I don't think it ought be attempted for
> such a critical, delicate procedure.

I personally think that preseed is nasty enough that users who do automation
on a scale that would make learning it worthwhile already have a better way to
do such automation.  For me, d-i is for manual installs, scripted stuff
wants a partitioner + glorified debootstrap.


I do have a different wish, though.  Could you please purge any references
to drivemakers' units (stuff like MiB = million bytes, which current
partitioner maliciously[1] swaps around with proper MB of 1048576B)? 
Having them in the user interface is deeply harmful: people will get
unoptimal alignment unless they 1. know about it, and 2. are careful enough. 
>From your comments before I see that you try to do proper alignment, but in
too many cases no matter how you try, the installer won't align well enough
because the hardware might be newer than the version of growlight, hide its
inner workings for marketing reason (like stealth SMR drives), etc.
On the other hand, a completely oblivious user will get good alignment if
you show numbers measured in gigabytes rather than gillionbytes.

I know of only one case of multi-GB alignment (some early versions of ipmctl
wanted a multiple of 32GB because certain vendor BIOSes had problems with
smaller blocks), but the required alignment there is 1GB for years.

And most importantly: thanks for this effort, it's greatly appreciated!


Meow.

[1]. The malice hasn't been invented by the implementor of the old
partitioner -- it was done by marketing departments of disk vendors in the
old days; they don't even do so anymore but as they tried going through
standard bodies while fighting lawsuits, some damage lingers on.  The fault
of our old partitioner is that it didn't filter out the malice.
-- 
⢀⣴⠾⠻⢶⣦⠀
⣾⠁⢠⠒⠀⣿⡁ A white dwarf seeks a red giant for a binary relationship.
⢿⡄⠘⠷⠚⠋⠀
⠈⠳⣄⠀⠀⠀⠀