Grub question (Ahem....help! Now it just says 'GRUB')

[Rick Stevens]

Mark Knecht wrote:
>>>OK, I now see Imissed on important piece of info. SC7 was installed in
>>>the MBR, and grub was installed (I think) on hda5. The boot process is
>>>to boot SC7, and then from SC7 choose Windows or Linux. If Linux, then
>>>it jumps to grub and I get the grub choices.
>>
>>I figured you'd have to complicate things. :-)
> 
> 
> <blush>
> 
>>>>>/dev/hda5 is marked as bootable, not hda7.
>>>>
>>>>I think that's irrelevant to GRUB.  Only your BIOS cares about that.
>>>>
>>>>
>>>>>The machine has been booted since I moved hda5 and hda6. Why
>>>>>did moving hda7 make any difference at all?
>>>>
>>>>I don't know.  Rick probably does.

You need to check the fstab and see if you're using labels or partition
numbers.  If you use partition numbers, moving hda7 may cause it to not
mount.

> I know Rick uses System Commander/Partition commander, but I'm unsure
> as to his use of their boot tools. He may use grub, or he may do it
> like I do. On a properly set up machine it's nice to use their tools
> as you have partition control at boot time, but that's jsut my
> preference. I was usign this tool set before I started with Linux. It
> was the only way to boot multiple copies of Windows. Later I jsut
> added Linux in the same way.

My laptop still has SC7, but it's not active (it's been grubified), so
I can't really get into it right now.

>>>>>2) What do I do to get the machine booting again?
>>>>
>>>>I'd say to boot with your distro disk #1 into rescue mode, let it
>>>>mount your system on /mnt/sysimage, pop out the CD, and then
>>>>
>>>> chroot /mnt/sysimage
>>>> grub-install /dev/hda
>>>
>>>This, I think, would put grub in the MBR, wouldn't it?
>>
>>Yes.  I've seen precious few reasons not to.  Yours may be one.
>>
>>
>>>If so that's
>>>not what I want to do, or at least I think I don't. I still want to
>>>boot SC7 first. How about
>>>
>>>grub-install /dev/hda5? (Or should it be hda7 since that's the
>>>partition that caused the problem when I moved it. That'swhat I'm
>>>confused about. What did grub really put on /dev/hda7?
>>>
>>>Or possibly grub really is on /dev/hda5, which moved successfully, but
>>>then moving hda7 caused grb to get confused? Does grub look at the
>>>actual location that the root partition exists at, or does it just use
>>>the partition number. (What I thought...)
>>
>>That's beyond my level of expertise.  Rick Stevens can chime in here.
>>The most important thing I can guess is that GRUB should be installed
>>on whichever partition is marked bootable.  (Yeah, now it matters, I
>>think.)  I still can't say which partition it should be.  The Fine
>>Manual

Remember, the BIOS of your machine will pass control to the MBR of the
primary drive.  Whatever is installed there is then responsible for
booting the rest of the stuff.  For grub to do the full boot duties, it
needs to be installed in the MBR of your primary hard drive.

If you want SC7 to do the booting, it must be installed on the MBR of
the primary hard drive.  grub must be in the root directory of whatever
partition you tell SC7 contains Linux, and you must tell SC7 which
partition that is.  It's usually pretty good at figuring it out, but
double check.  For most people, this would be the partition that
contains the /boot directory.

Sorry for my inactivity on the list the last few days, but it's been a
bit, well, "farking crazy" here.
----------------------------------------------------------------------
- Rick Stevens, Senior Systems Engineer     rstevens at vitalstream.com -
- VitalStream, Inc.                       http://www.vitalstream.com -
-                                                                    -
-         Okay, who put a "stop payment" on my reality check?        -
----------------------------------------------------------------------