on 10/10/2007 3:36 PM Hugh E Cruickshank spake the following:
From: Scott Silva Sent: October 10, 2007 15:15
on 10/10/2007 2:46 PM Hugh E Cruickshank spake the following:
From: Les Mikesell
Hugh E Cruickshank wrote:
From: Les Mikesell Sent: October 7, 2007 18:53
Then reinstall grub on the drive.
Now I have some questions:
1. Since the /boot partition was mirrored and will be restored on the
new sda drive I do not really want to do a full grub install. From
what I have read that will overwrite existing /boot/grub/grub.conf
file. So I just want to write the MBR on the drive. How to I do
that (the docs I have found were rather unclear on that aspect)?
2. Can a install grub on the replaced boot drive with the system still
running?
Yes, after the /boot partition re-sync has completed, execute grub and:
root (hd0,0)
setup (hd0)
quit
If you aren't able to keep the system running while doing the swap, you
can also do this from the rescue mode boot, but you should have the
contents on the /boot partition first.
Sorry to be obtuse here but I just want to make very sure of what I am
doing before I do it. Will the "setup" command only write the MBR?
>From my reading the GNU GRUB manual I got the distinct impression that
the "setup" command will also write/rewrite the /boot partition (which
I would like to avoid). The documentation for the setup command states:
Set up the installation of GRUB automatically. This command uses
the more flexible command install (see Section 13.3.18 [install],
page 44) in the backend and installs Chapter 13: The list of
available commands 49 GRUB into the device install device. If
image device is specified, then find the GRUB images (see Chapter
10 [Images], page 29) in the device image device, otherwise use the
current root device, which can be set by the command root. If
install device is a hard disk, then embed a Stage 1.5 in the disk
if possible.
The option �--prefix� specifies the directory under which GRUB
images are put. If it is not specified, GRUB automatically
searches them in �/boot/grub� and �/grub�.
The options �--force-lba� and �--stage2� are just passed to install
if specified. See Section 13.3.18 [install], page 44, for more
information.
The second paragraph tends to imply that /boot/grub will be written
to by default and I do not think that this is what I want to happen.
That paragraph should read stored not put. It assumes that the grub files
needed are already there.
The commands below work. grub-install and other variants are shell scripts to
accomplish the same thing.
Thanks again for everyone's input (especially Les). It is greatly
appreciated.
What "setup" command?
That would be the grub setup command.
You boot from a rescue disk if your system isn't running already.
If booting from rescue disk chroot to your installed files.
execute grub
at its prompt run the following;
root (hd0,0)
setup (hd0)
quit
That should let you boot into your stuff.
I know that will let me boot but that was not what I was asking about.
As per the documentation I quoted it appears that the grub setup
command will overwrite the /boot partition that has been restored from
the mirror drive. As far as I can see that is not desirable. All I want
to do is install the GRUB MBR and leave the contents of the /boot
partition intact.
My question is basically will the grub setup command only install the
MBR or will it also overwrite the /boot partition as well?
Regards, Hugh
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