MBR and grub-install

[Bruno Costacurta]

Hello,

I'm trying to install MBR and GRUB on another disk by making (from a third 
disk boot):

grub-install /dev/sda
grub ---> root(hd0,0)
grub ---> setup(hd0,0)

commands are accepted but doesn't work as PC continues to boot on my third 
disk. As far I understand grub-install should install MBR and grub commands 
should configured it.

- problem history: I had a two-disk (with LVM & RAID) with Fedora-6. As I 
installed distribution CentOS on a new third disk I now boot on CentOS via 
MBR on this third disk.

- what I'm looking for : I intend to recover previous MBR+GRUB on /dev/sda ( 
from previous Fedora install + setup) and then install CentOS entry into this 
grub configuration.

Thanks for attention.

Bye,
Bruno

[shhgs]

It is decided by BIOS that which disk to boot. Modify the "Boot
Sequence" option.

On 3/1/07, Bruno Costacurta  wrote:
> Hello,
>
> I'm trying to install MBR and GRUB on another disk by making (from a third
> disk boot):
>
> grub-install /dev/sda
> grub ---> root(hd0,0)
> grub ---> setup(hd0,0)
>
> commands are accepted but doesn't work as PC continues to boot on my third
> disk. As far I understand grub-install should install MBR and grub commands
> should configured it.
> problem history: I had a two-disk (with LVM & RAID) with Fedora-6. As I
>
> installed distribution CentOS on a new third disk I now boot on CentOS via
> MBR on this third disk.
> what I'm looking for : I intend to recover previous MBR+GRUB on /dev/sda (
>
> from previous Fedora install + setup) and then install CentOS entry into this
> grub configuration.
>
> Thanks for attention.
>
> Bye,
> Bruno
> --
> Bruno Costacurta
> PGP key : http://www.costacurta.org/keys/bruno_costacurta_pgp_key.html
> Key fingerprint = 713F 7956 9441 7DEF 58ED  1951 7E07 569B 2E60 4D51
> --
>
> --
> fedora-list mailing list
> [e-mail]
> To unsubscribe: https://www.redhat.com/mailman/listinfo/fedora-list

[Bruno Costacurta]

On Thursday 01 March 2007 12:29:11 shhgs wrote:
> It is decided by BIOS that which disk to boot. Modify the "Boot
> Sequence" option.

Does this means that the Linux install modifies the BIOS settings ?!?
Previously boot was from first disk, after CentOS install it is from third 
disk.
> On 3/1/07, Bruno Costacurta  wrote:
> > Hello,
> >
> > I'm trying to install MBR and GRUB on another disk by making (from a
> > third disk boot):
> >
> > grub-install /dev/sda
> > grub ---> root(hd0,0)
> > grub ---> setup(hd0,0)
> >
> > commands are accepted but doesn't work as PC continues to boot on my
> > third disk. As far I understand grub-install should install MBR and grub
> > commands should configured it.
> > problem history: I had a two-disk (with LVM & RAID) with Fedora-6. As I
> >
> > installed distribution CentOS on a new third disk I now boot on CentOS
> > via MBR on this third disk.
> > what I'm looking for : I intend to recover previous MBR+GRUB on
> >
> > /dev/sda ( from previous Fedora install + setup) and then install CentOS
> > entry into this grub configuration.
> >
> > Thanks for attention.
> >
> > Bye,
> > Bruno
> > --
> > Bruno Costacurta
> > PGP key : http://www.costacurta.org/keys/bruno_costacurta_pgp_key.html
> > Key fingerprint = 713F 7956 9441 7DEF 58ED  1951 7E07 569B 2E60 4D51
> > --
> >
> > --
> > fedora-list mailing list
> > [e-mail]
> > To unsubscribe: https://www.redhat.com/mailman/listinfo/fedora-list

[Dan Hensley]

On Thu, 2007-03-01 at 13:01 +0100, Bruno Costacurta wrote:
> On Thursday 01 March 2007 12:29:11 shhgs wrote:
> > It is decided by BIOS that which disk to boot. Modify the "Boot
> > Sequence" option.
>
> Does this means that the Linux install modifies the BIOS settings ?!?
> Previously boot was from first disk, after CentOS install it is from third 
> disk.

Also check the labels on your partitions.  Fedora labels the
partitions /USR, /HOME, etc. depending on how you partitioned it.  If
CentOS labeled them the same way (I guess it depends on what was
installed where and when), then it might find the wrong one and boot a
partition you weren't expecting.

I learned this recently when I cloned my Fedora hard drive and it kept
booting the old installation on a disk further down in the boot order.

Dan

[Mikkel]

Bruno Costacurta wrote:
> On Thursday 01 March 2007 12:29:11 shhgs wrote:
> > It is decided by BIOS that which disk to boot. Modify the "Boot
> > Sequence" option.
>
> Does this means that the Linux install modifies the BIOS settings ?!?
> Previously boot was from first disk, after CentOS install it is from third 
> disk.

I do not think that the installer modifies the BIOS settings. But if
you install the Grub fist stage to the MBR of the first disk, and
the rest of Grub is on the third disk, the system will start booting
 off the first disk, and transferrer control to the Grub second
stage on the third disk.

Mikkel