Date: Fri, 24 Nov 2000 10:11:20 -0700 (MST) From: Fred Clift <fclift@verio.net> To: Terry Lambert <tlambert@primenet.com> Cc: Fred Clift <fclift@verio.net>, opentrax@email.com, stable@FreeBSD.ORG, obrien@FreeBSD.ORG Subject: Re: Dedicated disks (was: Dangerously Dedicated) Message-ID: <Pine.BSF.4.21.0011240931550.3205-100000@vespa.orem.iserver.com> In-Reply-To: <200011240110.SAA05483@usr06.primenet.com>
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On Fri, 24 Nov 2000, Terry Lambert wrote:
> > > > o An increasing number of BIOS will divide by 0 when they
> > again, 30 seconds in fdisk fixes this
>
> This can be fixed, but hasn't been.
All I do is use disklabel to tell me the number of sectors, take that
value and stuff it into the 'length' field while changing the slice table
with fdisk -u and then let fdisk automatically round to the nearest
cylinder boundary. A couple of snippets from my custom install program
(at this point I already know how many sectors/unit there are, from a
previous disklable call...)
char fdiskcommand[] = "/sbin/fdisk -u da%d < /tmp/fdisk.in";
if ((fo = fopen("/tmp/fdisk.in","w")) == NULL)
fprintf(fo, "\n\n\n\ny\n\n\n%d\n\ny\n\ny\n",sectorsperunit);
sprintf(buff,fdiskcommand,device);
Note that this has been slightly altered from it's original form for
brevity and that if there are mistakes in it, it's because I too heavily
edited. Essentially, I just run fdisk -u and update the disklabel with
the right value. It has nothing to do with 'fixing' fdisk, but rather,
with understanding that hey, my hardware does want a valid slice table, so
why not give it one... (I'd need to go back and check but I think this
updates the geometry info to more valid settings too...)
>
>
> > > > o The FreeBSD fake DOS partition table does not pass a
> > > > number BIOS-based self-consistency checks (it needs to
...
> > again, 30 seconds in fdisk fixes this
> I don't agree with this one. There is a checksum that is not
> valid against the FreeBSD created partition tablem regardless
> of what you do with FreeBSD fdisk.
Are you saying that there are bioses out there that store the checksum of
the winX MBR and get grumpy if they dont find it? I guess it's
theoretically possible, but I'd not belive it till I saw it... The same
machine wouldn't run dr-dos, linux, os/2, beos, etc. I might understand a
bios being confused about boot1 only using slice 4, or perhaps being
confused that the MBR is _included_ in the only or active partition. It
probably wouldn't be that big of a deal to switch to using slice 1, but I
dont know if this would break other things. I personally haven't seen
bioses that are confused by having a slice that contains the mbr, but that
doesn't mean they dont exist. Just not on the hardware I play
with... And again, it's usually pretty easy to tell if your hadware
dislikes dedicated installs. If it works the first time, the system isn't
going to mysteriously stop working because of it later...
>
> I have yet to see a reasonable justification as to why a DOS
> partition table and MBR (or boot manager) causes any problems
> that can't be overcome.
So, aparently asthetics mean nothing to you? I personally get embarrassed
by ugly code and kludges. I have yet to see you 'refute', as you say
later in your mail, my arguments in another posting for the asthetic
reasons that people might have. Aparently the comleliness of the solution
to a problem provides no 'reasonable justification' to you. And really, I
guess it's no big deal. I dont have a neatness fetish for my own code,
but I know people who do. However, peoples sense of 'doing things the
right way' is a valid reason to keep support for this in the code...
I have no problem with making this less encouraged for newbies
to try, for making it a bit harder to do inintial installs in dedicated
mode. What I do have a problem with are people (not necessarily you, I'm
to lazy to go back and re-read the whole thread again...) that seem to
want to remove the ability to have this work even if you know what you're
doing...
I have already agreed that 'hey -- if you want to guarantee compatablity,
then just do it with a valid slice table'. Howver,I disagree with people
who say that that can't be a dedicated install. A dedicated install with
a valid slice table is probably about as compatable with any random piece
of hardware you pick up as a 'normal' install.
Dont take me too seriously though... :) I'm pretty much a nobody in the
FreeBSd world - just a very satisfied user who has fiddled with the part
of the system a lot.
Fred
--
Fred Clift - fclift@verio.net -- Remember: If brute
force doesn't work, you're just not using enough.
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