Re: Grub option on Debian-style install
Hello Marc,
On Wed, Sep 28, 2005 at 09:06:56AM +0100, marc wrote:
> > On Tuesday 27 September 2005 11:15 pm, marc wrote:
> >> >> I want to perform a Debian-style hard disk install of Knoppix v4. The
> >> >> machine currently has grub as boot-loader with XP and Debian
> >> >> installed.
> >> >>
> >> >> When I run the knoppix-installer the boot-loader options are limited
> >> >> to two:
> >> >> - MBR
> >> >> - Partition - to root-partition
> >> >>
> >> >> Clearly, I don't want to overwrite my existing MBR, since I want point
> >> >> to the scrip in Debian's /boot/grub script. However, I don't know what
> >> >> will happen should I select the second option. What I actuallt want to
> >> >> do is add a knoppix line to my existing grub script.
> >> >>
> >> >> How should I proceed? And what does the partition option o?
> >> >
> >> > Try Boot Magic in XP.
> >>
> >> What is Boot Magic and what would I use it for?
>
> > http://www.mega-tokyo.com/osfaq2/index.php/Boot Magic Boot Magic is
> > the bootloader that comes with the once famous "Partition Magic"
> > tool.
>
> I'm using grub, so I'm still unclear why you are mentioning this.
>
> >> As I mentioned, the machine is dual-boot XP and Debian already, it's
> >> only knoppix that I want to install (Debian-style).
>
> > In already installed Debian, you can edit /boot/grub//menu.lst :
> > Add, eg. my .lst file in Sarge
>
> I know how to edit the grub menu.
>
> The original question was that I do not know what knoppix-installer is
> going to do to my boot setup - specifically the second option, since
> the MBR overwrite seems clear. It hasn't done it yet because I don't
> know what it is going to do. That is what I'm asking: what does it do?
Frankly, the right person to ask would be Fabian Franz who wrote the
installer script. It always confuses me, and I don't really know why and
under which circumstances it is working. ;-)
But as it looks, the following is being done:
case $BOOT_WHERE in
partition)
grub-install --root-directory=$TARGET_MNT_POINT "$HD_CHOICE" >/dev/null 2>/dev/null || \
grub-install --root-directory=$TARGET_MNT_POINT "$HD_CHOICE" >/dev/null 2>/dev/null
;;
mbr)
grub-install --root-directory=$TARGET_MNT_POINT "(hd0)" >/dev/null 2>/dev/null
;;
esac
Which probably means that grub is installed on the partition record, not
the master boot record, in case you select "partition". This will not
work for all file systems, since not all of them have additional space
in the filesystem header for installing a bootloader. ext2 and reiserfs
should be safe, but I can't tell what happens if you try this with xfs
or jfs. It seems that Fabian forces installation on the master boot
record in these cases, which I think it not a good idea when the user
had selected "partition" before.
> What you describe is where I want to get to, but I'm not going to
> press the button on the installer until I know what it is going to do.
To be absolutely sure, you would have to read all parts and modules of
the installer script, check /usr/sbin/knoppix-installer and
everything under ./usr/share/knoppix-installer/*...
> To repeat:
> Clearly, I don't want to overwrite my existing MBR, since I want point
> to the scrip in Debian's /boot/grub script. However, I don't know what
> will happen should I select the second option. What I actually want to
> do is add a knoppix line to my existing grub script.
I hope the above sheds some light, and the "partition" option should be
safe - except if the file system on the partition in question is xfs or
jfs in which case it looks like the MBR is overwritten regardless of the
users choice. I found this out by studying "boot-tools.bm" from Fabians
installer.
You will probably still have to change your grub configuration manually.
The absolutely safest option would probably be to install NO bootloader
(if that's an option), and do everything manually by configuring your
existing grub configuration accordingly. If the file system you have
chosen for KNoppix is something that grub understands, you should be
able to add the correct entries for kernel and initrd without installinf
a partition bootloader. I think that Fabian just added the partition
option in order to be able to boot Linux from a Windows "boot.ini"
bootloader (or whatever this is called there).
Regards
-Klaus Knopper
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