[gentoo-user] another grub problem

[gentoo-user] another grub problem

[Allan Gottlieb]

The newest update of grub from 0.97-r5 to 0.97-r6 contained the 

     *** IMPORTANT NOTE: you must run grub and install
     the new version's stage1 to your MBR.  Until you do,
     stage1 and stage2 will still be the old version, but
     later stages will be the new version, which could
     cause problems such as an unbootable system.

Since this is only a change in the -r, I suspect that it is not
necessary to reinstall stage1, but I tried anyway and had trouble.
Since I thought I repeated steps that worked before, I am asking for
help/explanations.

I run grub and then the following dialog.

       GNU GRUB  version 0.97  (640K lower / 7168K upper memory)
   
    [ Minimal BASH-like line editing is supported.  For the first
      word, TAB lists possible command completions.  Anywhere else TAB
      lists the possible completions of a device/filename. ]
   
    grub> find /boot/grub/stage1
     (hd0,2)

As expected hd0 is the disk

    grub> setup (hd   <TAB>
     Possible disks are:  hd0 hd1

Again confirming that hd0 is a valid disk (as is hd1, but that is an
external scsi that does not contain stage1)

But now comes the problem.  (I want grub in the MBR.)

    grub> setup (hd0)

    Error 12: Invalid device requested

What is wrong?

I should add that I am following directions for installing grub
natively, which is supposed to be done using a "GRUB boot disk".  I
was trying it directly under gentoo, since I *think* that is what I
did last time.

I realize that the grub doc says that installing under the OS needs
grub-install.  I don't think I did this because of the somewhat
frightening

    *Caution:* This procedure is definitely less safe, because there
    are several ways in which your computer can become unbootable. For
    example, most operating systems don't tell GRUB how to map BIOS
    drives to OS devices correctly--GRUB merely "guesses" the
    mapping. This will succeed in most cases, but not
    always. Therefore, GRUB provides you with a map file called the
    "device map", which you must fix if it is wrong. *Note Device
    map::, for more details.

However, if that is everyone's recommendation I will of course try it.

(I don't have a floppy drive.  I do have a DVD+-RW, which naturally
works as a CDR.  So could use this if I could figure out how to use
xcdroast to create it).

thanks,
allan
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[gentoo-user] Re: another grub problem

[Allan Gottlieb]

At Sun, 06 Jul 2008 20:02:08 -0400 Allan Gottlieb <gottlieb@nyu.edu> wrote:

> The newest update of grub from 0.97-r5 to 0.97-r6 contained the 
>
>      *** IMPORTANT NOTE: you must run grub and install
>      the new version's stage1 to your MBR.  Until you do,
>      stage1 and stage2 will still be the old version, but
>      later stages will be the new version, which could
>      cause problems such as an unbootable system.
>
> Since this is only a change in the -r, I suspect that it is not
> necessary to reinstall stage1, but I tried anyway and had trouble.
> Since I thought I repeated steps that worked before, I am asking for
> help/explanations.
>
> I run grub and then the following dialog.
>
>        GNU GRUB  version 0.97  (640K lower / 7168K upper memory)
>    
>     [ Minimal BASH-like line editing is supported.  For the first
>       word, TAB lists possible command completions.  Anywhere else TAB
>       lists the possible completions of a device/filename. ]
>    
>     grub> find /boot/grub/stage1
>      (hd0,2)
>
> As expected hd0 is the disk
>
>     grub> setup (hd   <TAB>
>      Possible disks are:  hd0 hd1
>
> Again confirming that hd0 is a valid disk (as is hd1, but that is an
> external scsi that does not contain stage1)
>
> But now comes the problem.  (I want grub in the MBR.)
>
>     grub> setup (hd0)
>
>     Error 12: Invalid device requested
>
> What is wrong?


I have now downloaded the 2008.0 livecd.  I booted from it and ran
grub.
Again the find returns (hd0,2) and alas the setup (hd0) returns the
same error message.

allan
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Re: [gentoo-user] Re: another grub problem: SOLVED

[Allan Gottlieb]

(Summary: I had a problem with installing grub into the MBR.
Two thoughtful replies set me straight)

At Mon, 07 Jul 2008 08:46:34 +0100 Neil Bothwick <neil@digimed.co.uk> wrote:

> On Sun, 06 Jul 2008 20:02:08 -0400, Allan Gottlieb wrote:
>
>>     grub> find /boot/grub/stage1  
>>      (hd0,2)
>> 
>> As expected hd0 is the disk
>
> You should now run "root (hd0,2)"
>
>>     grub> setup (hd   <TAB>  
>>      Possible disks are:  hd0 hd1
>> 
>> Again confirming that hd0 is a valid disk (as is hd1, but that is an
>> external scsi that does not contain stage1)
>> 
>> But now comes the problem.  (I want grub in the MBR.)
>> 
>>     grub> setup (hd0)  
>> 
>>     Error 12: Invalid device requested
>> 
>> What is wrong?
>
> GRUB can't find its files because you haven't told it which partition
> contains them. Only the stage1 goes into the MBR, along with a pointer to
> the partition that contains everything else.

At Mon, 07 Jul 2008 08:47:44 +0200 Sebastian Günther <samson@guenther-roetgen.de> wrote:

> * Allan Gottlieb (gottlieb@nyu.edu) [07.07.08 02:03]:
>>     grub> find /boot/grub/stage1
>>      (hd0,2)
>> 
>> As expected hd0 is the disk
>> 
>>     grub> setup (hd   <TAB>
>>      Possible disks are:  hd0 hd1
>> 
>> Again confirming that hd0 is a valid disk (as is hd1, but that is an
>> external scsi that does not contain stage1)
>> 
>> But now comes the problem.  (I want grub in the MBR.)
>> 
>>     grub> setup (hd0)
>> 
>> What is wrong?
>> 
> maybe you just forgot:
>
>    grub> root hd(hd0,2)
>
> to say grub where the stages should end up?

Thank you sebastian and neil for your clear responses, which worked
perfectly.

allan
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Re: [gentoo-user] another grub problem

[Sebastian Günther]

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* Allan Gottlieb (gottlieb@nyu.edu) [07.07.08 02:03]:
>     grub> find /boot/grub/stage1
>      (hd0,2)
> 

> As expected hd0 is the disk
> 
>     grub> setup (hd   <TAB>
>      Possible disks are:  hd0 hd1
> 
> Again confirming that hd0 is a valid disk (as is hd1, but that is an
> external scsi that does not contain stage1)
> 
> But now comes the problem.  (I want grub in the MBR.)
> 
>     grub> setup (hd0)
> 
> 
> What is wrong?
> 
maybe you just forgot:

   grub> root hd(hd0,2)

to say grub where the stages should end up?

Sebastian

-- 
 " Religion ist das Opium des Volkes. "      Karl Marx

 SEB@STI@N GÜNTHER         mailto:samson@guenther-roetgen.de

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Re: [gentoo-user] another grub problem

[Neil Bothwick]

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On Sun, 06 Jul 2008 20:02:08 -0400, Allan Gottlieb wrote:

>     grub> find /boot/grub/stage1  
>      (hd0,2)
> 
> As expected hd0 is the disk

You should now run "root (hd0,2)"

>     grub> setup (hd   <TAB>  
>      Possible disks are:  hd0 hd1
> 
> Again confirming that hd0 is a valid disk (as is hd1, but that is an
> external scsi that does not contain stage1)
> 
> But now comes the problem.  (I want grub in the MBR.)
> 
>     grub> setup (hd0)  
> 
>     Error 12: Invalid device requested
> 
> What is wrong?

GRUB can't find its files because you haven't told it which partition
contains them. Only the stage1 goes into the MBR, along with a pointer to
the partition that contains everything else.


-- 
Neil Bothwick

Q. How do you identify a blind man in a nudist colony?
A. It's not hard.

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