[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: Partitioning

get me off this list

Gertjan Klein wrote:

> Bill Leach <bleach@bellsouth.net> wrote:
>  > On Wed, 10 Dec 1997, Gertjan Klein wrote:
>  > Obviously
>  > these are judgement calls and opinions but when the original hard disk code
>  > was written decisions were made concerning such things as sizes for device
>  > storage parameters.  While what you have said about the cost of 10Meg HDs
>  > and the like is true, that fact did not seem to influence others in such a
>  > limiting way about how to deal with the matter.  More importantly, I
>  > think, is that it has taken many years to finally to address this issue.
>   The original harddisk code was written for (relatively) cheap
> hardware.  SCSI harddisks, using block addressing, were of course
> around, but much more expensive.  Nevertheless, even though the
> partition table entries specify the location of partitions in cylinder,
> head, and sector parameters, they _also_ specify them in logical block
> numbers.  Using these numbers a harddisk of 2 TB (2048 GB) can be
> described.  Note, again, that the partition table layout has nothing to
> do with the BIOS.  The BIOS provided an interface for cheap hardware; if
> demand would have been higher for better quality hardware, like built-in
> support for SCSI drives, it would have been there.  Nothing in the PC
> design prevents this - in fact, my BIOS directly supports (NCR) SCSI
> controllers.  On top of that, the PC design allows for _really_ non
> standard (for PC's, anyway) hardware to have it's own BIOS to take over
> the standard BIOS calls.
>  >> I'm not exactly sure what you think is the nightmare part of the
>  >> original design (and frankly, I don't care).  There are a ...
>  > And if you don't care then we are probably both wasting our time.
>   No - because I am not trying to change your _opinion_ on PC hardware,
> I am just trying to stop you from spreading misinformation about it.  I
> realize very well that a lot of compromises have been made with PC
> design over the years, there is enough to complain about - so if you
> want to do that, go ahead, but get your facts straight.
>  >> * There is a limited number of primary partitions available in the MBR.
>  >> This limitation is no serious problem, as many modern OSes don't object
>  >> to being installed in an extended partition (of which there can be as
>  >> many as required).
>  > Yes, many often incompatible workarounds exist.
>   What do you mean with "incompatible workarounds"?  What's incompatible
> about booting from an extended partition?
>  > No there is nothing brain dead about partitioning a drive and I see no way
>  > that anyone could conclude from anything that I have said that I think
>  > otherwise.  It is the arbitrary decision to create the "tiered" partition
>  > types (primary, extended, and logical) abstraction that I object to.
>   Since the partition table resides in the MBR, with limited space,
> _some_ limit had to be set to the number of entries in the table.  Four,
> at the time, was a reasonable limit.  When the limit became - well,
> limiting, MS introduced extended partitions - which is nothing other
> than a way to arbitrarily expand the partition table.  It seems like a
> reasonable solution to me.
>  > These "modern BIOSes" have finally caught up with BIOSes of more than
>  > twenty years ago.  Are you suggesting that had different decisions
>  > concerning how to deal compatibly with the various limitation that were
>  > arbitrarily built into the original design had been handled differently
>  > that the PC would not be as popular or have such a favorable
>  > performance/price ratio as it currently has?
>   Yes.  (I don't want to get into this, though, because there is no way
> to prove one way or the other).
>  > I have "lost it".  In as much as I really do not wish to mislead anyone
>  > then by "misinformation" are you talking about my assertions with respect
>  > to the BIOS design (and indeed design evolution) upon the overall
>  > filesystem design, or rather my (admitted) failure to even mention that
>  > there are new BIOS designs that do not themselves impose this scheme, or
>  > both?
>   Your misinformation was that:
>  - BIOS imposes the current partitioning scheme opon us, and limits the
> number of primary partitions to four (not true - BIOS knows nothing
> about partitions and doesn't care either).
>  - DOS, Windows and OS/2 don't see other primary partitions than the one
> they booted from (not true - DOS and Windows see other primary DOS
> partitions just fine, and OS/2 won't even boot when they are present and
> not "hidden").
>  - fdisk /mbr will wipe out everything on the drive (wrong - it just
> replaces (or installs) the MBR software without touching the partition
> table).
>  - (A point I hadn't addressed yet:) loadlin uses BIOS calls for drive
> access (wrong - it uses DOS calls, which can, but don't have to,
> translate into BIOS calls).
>   You _still_ don't seem to get that partitioning and BIOS have nothing
> to do with each other, and that the BIOS is simply just a piece of
> software - if the current interface is not longer sufficient, it is very
> easy to change the BIOS to provide a new interface, or extend the
> current one.  This has happened already - if it happened too late to
> your liking, complain about the market forces that dictated the
> development direction.  The older XT BIOSes were around 8 kB - current
> BIOSes can be as large as 1 MB.  Things _have_ changed.
>  > As I pointed out in the previous message, I have seen many PCs with
>  > multiple primary partitions where only ONE primary partition is visible to
>  > DOS or Windoz (or OS2 for that matter).
>   This may be a silly question, but are these other partitions DOS
> partitions?  If not, why do you expect DOS to natively support non-DOS
> filesystems?  If they are, the only explanation I can give is that the
> used boot manager (presumably OS/2's, but mine can do that too) hides
> the other partitions.
> [Hardware behaving sub-standard and incompatible]
>   No argument from me here (other than that this, again, is not inherent
> to PC design but to manufacturers selling hardware that is not up to
> standard, presumably to make it cheaper).
>  > In a sense all of this opinion matters not.  The PC is what it is and it
>  > does seem to be evolving in the "right" direction even if it has taken
>  > nearly 15 years to do make significant progress.
>   You are right, all these opinions don't matter, and worse, are
> off-topic.  I apologize for not sticking to the point I was trying to
> make, which is not to refute your opinions about the PCs, but to correct
> the errors described above.
>   Gertjan.
> --
> Gertjan Klein <gklein@xs4all.nl>
> The Boot Control home page: http://www.xs4all.nl/~gklein/bcpage.html
> --
> TO UNSUBSCRIBE FROM THIS MAILING LIST: e-mail the word "unsubscribe" to
> debian-user-request@lists.debian.org .
> Trouble?  e-mail to templin@bucknell.edu .

TO UNSUBSCRIBE FROM THIS MAILING LIST: e-mail the word "unsubscribe" to
debian-user-request@lists.debian.org . 
Trouble?  e-mail to templin@bucknell.edu .

Reply to: