svn commit: r195817 - head/usr.sbin/sysinstall

[Scott Long]

M. Warner Losh wrote:
> In message: <4A6A7F2D.90807 at samsco.org>
>             Scott Long <scottl at samsco.org> writes:
> : M. Warner Losh wrote:
> : > In message: <4A68DA56.60301 at samsco.org>
> : >             Scott Long <scottl at samsco.org> writes:
> : > : M. Warner Losh wrote:
> : > : > In message: <4A66D0F4.4030108 at FreeBSD.org>
> : > : >             Alexander Motin <mav at FreeBSD.org> writes:
> : > : > : Colin Percival wrote:
> : > : > : > Author: cperciva
> : > : > : > Date: Wed Jul 22 03:50:54 2009
> : > : > : > New Revision: 195817
> : > : > : > URL: http://svn.freebsd.org/changeset/base/195817
> : > : > : > 
> : > : > : > Log:
> : > : > : >   Remove the "dedicated disk mode" partitioning option from sysinstall, in
> : > : > : >   both the disk partitioning screen (the 'F' key) and via install.cfg (the
> : > : > : >   VAR_DEDICATED_DISK option).  This functionality is currently broken in 8.x
> : > : > : >   due to libdisk and geom generating different partition names; this commit
> : > : > : >   merely acts to help steer users away from the breakage.
> : > : > : >   
> : > : > : >   Submitted by:	randi
> : > : > : >   Approved by:	re (kensmith)
> : > : > : > 
> : > : > : > Modified:
> : > : > : >   head/usr.sbin/sysinstall/disks.c
> : > : > : 
> : > : > : Is there any other way to not align FS block to the ugly legacy 63
> : > : > : sectors per track boundary with sysinstall now? I think RAIDs won't be
> : > : > : happy. May be it would be better to fix it?
> : > : > 
> : > : > The reason we do it like this is because the boot blocks occupy the
> : > : > first cylinder group.  Which with today's fake goemetry is 63
> : > : > blocks...
> : > : > 
> : > : 
> : > : I already covered this.  Unfortunately, Randi didn't take my bait. 
> : > : Anyways, '63' is a minimum, it's not a singular value.  It's also
> : > : an incredibly bad default.
> : > 
> : > Yes.  256 is just as good as 63, unless the geometry reports more than
> : > 256 heads, which I don't think is possible...
> : > 
> : > Warner
> : 
> : If there is a BIOS in existence that can't find sector 256, then it 
> : likely can't boot off of anything other than partition 1 in the fdisk
> : table.  I bet that bugs like that were likely caught 15-20 years ago.
> 
> I think you were missing the point I was trying to make, I must have
> been unclear.
> 
> If there were more than 256 sectors in the first cylinder, then
> starting at 256 would overlap.  This is largely a theoretical
> problem, I think, since I don't think that the BIOS can report a
> geometry > 64.
> 
> The only issue that I can think of is that FreeBSD's fdisk wants to
> have things on cylinder boundaries, which 256 isn't, so fdisk will
> bitch and moan...
> 
> Warner

Ah, we will never be freed of the CHS bonds, will we.  Oh well.

Scott