BOIS Blues again

[Karl Larsen]

    Here is what worked for years: The Grub was on disk hd0 and Linux 
was on hd0,0 thru 6 and hd1,0 thru 7. The BIOS could find all the Linux 
/boot/grub/ without fail.

    Now I have just one hard drive all set in the BIOS setup and I went 
up in the F7 Rescue cd and told grub the following:

Grub> root (hd0,5)
Grub> setup (hd0)
Grub> quit

This worked according to the written info from grub. But It would not 
work. I would get a bios error.

    So I installed FC6 basic in the (hd0,0) partition and it worked 
fine. Then I added the directions to this F7 and of course Grub found 
it. Here I am again on the old computer.

-- 

	Karl F. Larsen, AKA K5DI
	Linux User
	#450462   http://counter.li.org.

[Aaron Konstam]

On Sat, 2007-08-25 at 11:28 -0600, Karl Larsen wrote:
>  Here is what worked for years: The Grub was on disk hd0 and Linux 
>  was on hd0,0 thru 6 and hd1,0 thru 7. The BIOS could find all the Linux 
>  /boot/grub/ without fail.
>  
>      Now I have just one hard drive all set in the BIOS setup and I went 
>  up in the F7 Rescue cd and told grub the following:
>  
>  Grub> root (hd0,5)
>  Grub> setup (hd0)
>  Grub> quit
>  
>  This worked according to the written info from grub. But It would not 
>  work. I would get a bios error.
>  
>      So I installed FC6 basic in the (hd0,0) partition and it worked 
>  fine. Then I added the directions to this F7 and of course Grub found 
>  it. Here I am again on the old computer. 
This would work only if the grub boot
block was partition 5 and you had
another boot loader that would know to go to partition 5 to look for the
grub boot block. I can't believe you read instructions that told you to
do this.
--
=======================================================================
Men often believe -- or pretend -- that the "Law" is something sacred,
or at least a science -- an unfounded assumption very convenient to
governments.
=======================================================================
Aaron Konstam telephone: [phone] e-mail: akonstam(a)sbcglobal.net

[Karl Larsen]

Aaron Konstam wrote:
>  On Sat, 2007-08-25 at 11:28 -0600, Karl Larsen wrote:
>    
> > Here is what worked for years: The Grub was on disk hd0 and Linux 
> > was on hd0,0 thru 6 and hd1,0 thru 7. The BIOS could find all the Linux 
> > /boot/grub/ without fail.
> >
> >     Now I have just one hard drive all set in the BIOS setup and I went 
> > up in the F7 Rescue cd and told grub the following:
> >
> > Grub> root (hd0,5)
> > Grub> setup (hd0)
> > Grub> quit
> >
> > This worked according to the written info from grub. But It would not 
> > work. I would get a bios error.
> >
> >     So I installed FC6 basic in the (hd0,0) partition and it worked 
> > fine. Then I added the directions to this F7 and of course Grub found 
> > it. Here I am again on the old computer.
> >     
>  This would work only if the grub boot block was partition 5 and you had
>  another boot loader that would know to go to partition 5 to look for the
>  grub boot block. I can't believe you read instructions that told you to
>  do this.
>     
    Well as it works out I found out how to have the root 10,000 
cylinders away from the MBR and it works just fine with my old bios. 
Right now I'm using grub in partition /dev/sda6/ to boot and it works 
fine because while in /dev/sda6/ I typed grub-install and it did it right!

    This is why I fear an error on my part or a bug for grub.


>  --
>  =======================================================================
>  Men often believe -- or pretend -- that the "Law" is something sacred,
>  or at least a science -- an unfounded assumption very convenient to
>  governments.
>  =======================================================================
>  Aaron Konstam telephone: [phone] e-mail: akonstam(a)sbcglobal.net
>
>     

-- 

	Karl F. Larsen, AKA K5DI
	Linux User
	#450462   http://counter.li.org.

[Rick Stevens]

On Sat, 2007-08-25 at 16:02 -0600, Karl Larsen wrote:
>  Aaron Konstam wrote:
>  > On Sat, 2007-08-25 at 11:28 -0600, Karl Larsen wrote:
>  >   
>  >> Here is what worked for years: The Grub was on disk hd0 and Linux 
>  >> was on hd0,0 thru 6 and hd1,0 thru 7. The BIOS could find all the Linux 
>  >> /boot/grub/ without fail.
>  >>
>  >>     Now I have just one hard drive all set in the BIOS setup and I went 
>  >> up in the F7 Rescue cd and told grub the following:
>  >>
>  >> Grub> root (hd0,5)
>  >> Grub> setup (hd0)
>  >> Grub> quit
>  >>
>  >> This worked according to the written info from grub. But It would not 
>  >> work. I would get a bios error.
>  >>
>  >>     So I installed FC6 basic in the (hd0,0) partition and it worked 
>  >> fine. Then I added the directions to this F7 and of course Grub found 
>  >> it. Here I am again on the old computer.
>  >>     
>  > This would work only if the grub boot block was partition 5 and you had
>  > another boot loader that would know to go to partition 5 to look for the
>  > grub boot block. I can't believe you read instructions that told you to
>  > do this.
>  >   
>  
>      Well as it works out I found out how to have the root 10,000 
>  cylinders away from the MBR and it works just fine with my old bios. 
>  Right now I'm using grub in partition /dev/sda6/ to boot and it works 
>  fine because while in /dev/sda6/ I typed grub-install and it did it right!
>  
>      This is why I fear an error on my part or a bug for grub. 
This is not a bug in grub.  Your BIOS can only boot from a bootblock
that's within the first 1024 CYLINDERS, regardless of which block it is.
This is one of the reasons that the HDA mode of your hard drive was
invented.  In HDA mode, the drive can mask its true geometry and make
every block of the entire disk appear as though its in the first 1024
cylinders.

If grub is your only boot loader, it should be placed in the master boot
record (MBR) of your first hard drive (or whichever drive you tell your
BIOS it should boot from).  The MBR is the first usable block of the
drive.  Once the first-level grub loader is in the memory, it can boot
any second-level loader from anywhere on the disk (or any disk).  Grub
doesn't have the 1024 cylinder or number-of-drives limit that BIOS does.

----------------------------------------------------------------------
- Rick Stevens, Principal Engineer             rstevens(a)internap.com -
- CDN Systems, Internap, Inc.                http://www.internap.com -
-                                                                    -
-      Batteries not included.  Offer not valid in some states.      -
-           Your mileage may vary.  Void where prohibited.           -
----------------------------------------------------------------------

[Mikkel]

Rick Stevens wrote:
>  On Sat, 2007-08-25 at 16:02 -0600, Karl Larsen wrote:
> > Aaron Konstam wrote:
> >> On Sat, 2007-08-25 at 11:28 -0600, Karl Larsen wrote:
> >>   
> >>> Here is what worked for years: The Grub was on disk hd0 and Linux 
> >>> was on hd0,0 thru 6 and hd1,0 thru 7. The BIOS could find all the Linux 
> >>> /boot/grub/ without fail.
> >>>
> >>>     Now I have just one hard drive all set in the BIOS setup and I went 
> >>> up in the F7 Rescue cd and told grub the following:
> >>>
> >>> Grub> root (hd0,5)
> >>> Grub> setup (hd0)
> >>> Grub> quit
> >>>
> >>> This worked according to the written info from grub. But It would not 
> >>> work. I would get a bios error.
> >>>
> >>>     So I installed FC6 basic in the (hd0,0) partition and it worked 
> >>> fine. Then I added the directions to this F7 and of course Grub found 
> >>> it. Here I am again on the old computer.
> >>>     
> >> This would work only if the grub boot block was partition 5 and you had
> >> another boot loader that would know to go to partition 5 to look for the
> >> grub boot block. I can't believe you read instructions that told you to
> >> do this.
> >>   
> >     Well as it works out I found out how to have the root 10,000 
> > cylinders away from the MBR and it works just fine with my old bios. 
> > Right now I'm using grub in partition /dev/sda6/ to boot and it works 
> > fine because while in /dev/sda6/ I typed grub-install and it did it right!
> >
> >     This is why I fear an error on my part or a bug for grub.
>  
>  This is not a bug in grub.  Your BIOS can only boot from a bootblock
>  that's within the first 1024 CYLINDERS, regardless of which block it is.
>  This is one of the reasons that the HDA mode of your hard drive was
>  invented.  In HDA mode, the drive can mask its true geometry and make
>  every block of the entire disk appear as though its in the first 1024
>  cylinders.
>  
>  If grub is your only boot loader, it should be placed in the master boot
>  record (MBR) of your first hard drive (or whichever drive you tell your
>  BIOS it should boot from).  The MBR is the first usable block of the
>  drive.  Once the first-level grub loader is in the memory, it can boot
>  any second-level loader from anywhere on the disk (or any disk).  Grub
>  doesn't have the 1024 cylinder or number-of-drives limit that BIOS does.
>   
Most newer BIOS support LBA addressing. This gets rid of the 1024
cylinder limit, but may give another limit, depending on how the
BIOS implements it. There were also problems with the way some BIOS
reported HDA/LBA availability. I think they are fixed, but I have
not tested it. I just create a /boot partition at the beginning of
the drive and forget about it...

Mikkel
-- 

  Do not meddle in the affairs of dragons,
for thou art crunchy and taste good with Ketchup!

[Tim]

On Mon, 2007-08-27 at 10:27 -0700, Rick Stevens wrote:
>  The MBR is the first usable block of the drive.  Once the
> first-level
>  grub loader is in the memory, it can boot any second-level loader from
>  anywhere on the disk (or any disk).  Grub doesn't have the 1024
>  cylinder or number-of-drives limit that BIOS does. 
Others have suggested that it still does, that it must use the BIOS to
further access the drive.  That's why we have GRUB *and* the kernel
files in the small /boot partition.  It's the Linux kernel that can use
the rest of the drive.

-- 
[tim@bigblack ~]$ uname -ipr
2.6.22.1-41.fc7 i686 i386

Using FC 4, 5, 6 & 7, plus CentOS 5.  Today, it's FC7.

Don't send private replies to my address, the mailbox is ignored.
I read messages from the public lists.

[Mike McCarty]

Rick Stevens wrote:

[snip]

>  If grub is your only boot loader, it should be placed in the master
> boot
>  record (MBR) of your first hard drive (or whichever drive you tell your
>  BIOS it should boot from).  The MBR is the first usable block of the
>  drive.  Once the first-level grub loader is in the memory, it can boot
>  any second-level loader from anywhere on the disk (or any disk).  Grub
>  doesn't have the 1024 cylinder or number-of-drives limit that BIOS does. 
Erm, GRUB can load it in; that doesn't mean that the boot loader
will run as desired in the environment GRUB provides. The setup you
specify usually works, but not always. On my machine, for example, it
results in a prompt to repair the disc.

Mike
-- 
p="p=%c%s%c;main(){printf(p,34,p,34);}";main(){printf(p,34,p,34);}
Oppose globalization and One World Governments like the UN.
This message made from 100% recycled bits.
You have found the bank of Larn.
I can explain it for you, but I can't understand it for you.
I speak only for myself, and I am unanimous in that!