Re: fdisk(8) no longer capable of altering geometry

From: Deomid Ryabkov <myself_at_rojer.pp.ru>
Date: Mon, 14 Nov 2005 12:36:23 +0300
Simon L. Nielsen wrote:
> On 2005.11.12 01:19:52 +0100, Dario Freni wrote:
>   
>> My little follow-up to this issue. This bug is quite critical on 
>> products using bsdinstaller such as FreeSBIE or pfSense. I heard rumours 
>> that PC-BSD also encounter this problem and had to workaround it by 
>> sysinstall.
>>
>> Can somebody please take a look at it?
>>     
>
> Just curious... why do you need to alter the geometry?  I never once
> had a problem just ignoring the fact that fdisk/sysinstall warned
> about geometry...
>   
sysinstall warns and fixes it for you. i had to duplicate sysinstall's 
behavior in my home-made quick'n'dirty installer
or otherwise disks larger than (some size, like 60G, i don't remember 
exactly) are not bootable after install.
the fixup, rewritten in perl, looks like this:

print "geom: cyl=$cyl, hd=$hd, sect=$sect\n";
if ($cyl > 1024 or $hd > 16 or $sect > 63) {
        $hd = 16; $sect = 63;
        $cyl = int ($size / ($hd * $sect));
        if ($cyl > 1024) {
                $hd = 255;
                $cyl = int ($size / ($hd * $sect));
        }
        print "new geom: cyl=$cyl, hd=$hd, sect=$sect\n";
        _at_ret = ($cyl, $hd, $sect);
}

i don't know the exact meaning of ths, but it is indeed required to be 
able to boot off the disk.

--
Deomid Ryabkov aka Rojer
myself_at_rojer.pp.ru
rojer_at_sysadmins.ru
ICQ: 8025844


Received on Mon Nov 14 2005 - 08:36:32 UTC

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