Re: Daily digest, Issue 3641 (37 messages)

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Re: Daily digest, Issue 3641 (37 messages)

alan01346
re: bootable cylinder limit?

All manner of things seem to have broken when I went from a 500 gig
drive to 1 TB, or maybe it's because I added Linux.  For years I've
been using the method that used to be in the OpenBSD FAQ of using dd
to write out the first sector of the partition you want to boot to a
file, copying that into the Windows partition, then setting it up in
Windows boot.ini.  It worked this time for a week or so, and only
Linux broke, OpenBSD and Windows still work.

I used lilo because it was willing to install into the Linux
partition, not the MBR.  That might be possible with grub, I'm now
reading http://www.gnu.org/software/grub/manual/grub.html.  Seems like
I might need to chain load grub from the Windows bootloader.  I wanted
each OS self-contained so as a last resort if I flagged that partition
bootable the OS installed there would boot, or I could link a copied
bootsector from boot.ini.

I've used lilo (and loadlin) before, not grub.  Grub seemingly won't
boot Windows, it has to be the other way around. I did get lilo up by
putting the Debian install CD back in and it seems limited to LBA32,
not LBA48 as dmesg shows my drive using.  Yes, the problem with LBA,
not CHS, is that you need really big (unsigned) integers.

I hate it when you want to return to a simpler way of life and find it
doesn't work anymore.  I have a bootable floppy image from Windows 95
so I just tried to set that up as the bootable part of a CD (worked
before) so I could run Norton Utilities to look at the MBR.  Comes up
not finding command.com.  Same thing happens with a Dell Diagnostics
CD I made in 2008.  All this fancy crap...

--
Credit is the root of all evil.  - AB1JX

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Re: Daily digest, Issue 3641 (37 messages)

Adam Van Ymeren
On Tue, Nov 24, 2015 at 1:42 PM, Alan Corey <[hidden email]> wrote:

> re: bootable cylinder limit?
>
> All manner of things seem to have broken when I went from a 500 gig
> drive to 1 TB, or maybe it's because I added Linux.  For years I've
> been using the method that used to be in the OpenBSD FAQ of using dd
> to write out the first sector of the partition you want to boot to a
> file, copying that into the Windows partition, then setting it up in
> Windows boot.ini.  It worked this time for a week or so, and only
> Linux broke, OpenBSD and Windows still work.
>
> I used lilo because it was willing to install into the Linux
> partition, not the MBR.  That might be possible with grub, I'm now
> reading http://www.gnu.org/software/grub/manual/grub.html.  Seems like
> I might need to chain load grub from the Windows bootloader.  I wanted
> each OS self-contained so as a last resort if I flagged that partition
> bootable the OS installed there would boot, or I could link a copied
> bootsector from boot.ini.
>
> I've used lilo (and loadlin) before, not grub.  Grub seemingly won't
> boot Windows, it has to be the other way around. I did get lilo up by

GRUB should be able to boot windows.  I've had grub installed to the
MBR and used the chainloader command to load the windows bootloader.

> putting the Debian install CD back in and it seems limited to LBA32,
> not LBA48 as dmesg shows my drive using.  Yes, the problem with LBA,
> not CHS, is that you need really big (unsigned) integers.
>
> I hate it when you want to return to a simpler way of life and find it
> doesn't work anymore.  I have a bootable floppy image from Windows 95
> so I just tried to set that up as the bootable part of a CD (worked
> before) so I could run Norton Utilities to look at the MBR.  Comes up
> not finding command.com.  Same thing happens with a Dell Diagnostics
> CD I made in 2008.  All this fancy crap...
>
> --
> Credit is the root of all evil.  - AB1JX

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Re: Daily digest, Issue 3641 (37 messages)

Peter Kay-5
 Yes, it is possible for grub to boot Windows. LILO too, it can even boot Xen if you use mbootpack (otherwise it doesn't support initrd).

The point is that if you use Windows you must use its boot menu, and it's easier to configure it to boot multiple OS than grub or lilo. EasyBSD handles all the boot blocks for you.
--
Sent from my Android device with K-9 Mail. Please excuse my brevity.

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Re: Daily digest, Issue 3641 (37 messages)

alan01346
re: bootable cylinder limit?

>The point is that if you use Windows you must use its boot menu, and it's
> easier to configure it to boot multiple OS than grub or lilo. EasyBSD
> handles all the boot blocks for you.

One problem is that everything is old (including me).  The computers
are from 2003 and 2008, they get hard drives replaced every few years
before they wear out.  Windows is XP (Pro, sp 3) because I don't spend
money on Microsoft products.  The computers came with COA stickers for
XP, that's what I use.  EasyBCD does nothing, it won't even install
under XP.

I've been multibooting for 15 years, that in itself isn't the problem,
I've done it many times.  I probably won't try FreeBSD and OpenBSD
together again.  Mostly I use one tool to make my partitions and a
second one to check up on it, looking for things like overlapped
partitions and partitions not ending on cylinder boundaries.  As disks
get bigger the tools have to be replaced.  My favorite until this
drive was gdisk by Symantek, part of the Ghost package.  This time I
used Gparted http://gparted.org/ and it looks OK so far, I used the
live Linux CD version.  Make the partitions right and even Windows
will live with them, but I always install it first because it has a
history of obliterating other operating systems on the same drive.
And let it run the show, use its boot menu, start other operating
systems from boot.ini.

The problem is that every computer's BIOS can only allocate X number
of bits for storing things like a cylinder number or (worse) an LBA.
Historically there have always been limits, sometimes you can update
the motherboard's BIOS and that helps a little.  There was one at 540
MB.  But these limits are rarely published because partly they depend
on the BIOS and partly the drive geometry.  Drive geometry isn't
absolute, you don't have to stick with hardware reality.  Too many
heads?  Cut it in half and double the cylinders instead.  That's not
always wise but it's been done.  The manufacturers put the limit so
high it won't be a problem, but then drives get bigger.  My first hard
drive was 20 megabytes, now I have some 6(?) orders of magnitude
bigger,

Write something in assembly using only BIOS interrupts (no operating
system) that gets hooked by the BIOS when booting to start it, it
tries to access higher and higher LBAs until it fails, meanwhile
logging.  I taught myself x86 assembly language about 1994, haven't
used it since, but it sounds possible.  I used the A86, Masm, Tasm
assemblers, not nasm, but to me the thrill of assembly is that things
happen instantly when the program's running.  My new fast machine was
a 40 MHz 386 SX motherboard with a brand new 200 megabyte hard drive.
I pounded a lot of nails, did a lot of grunt work, to earn it.

On 11/25/15, Peter Kay <[hidden email]> wrote:
>  Yes, it is possible for grub to boot Windows. LILO too, it can even boot
> Xen if you use mbootpack (otherwise it doesn't support initrd).
>
> The point is that if you use Windows you must use its boot menu, and it's
> easier to configure it to boot multiple OS than grub or lilo. EasyBSD
> handles all the boot blocks for you.
> --
> Sent from my Android device with K-9 Mail. Please excuse my brevity.


--
Credit is the root of all evil.  - AB1JX