[gentoo-user] Grub boots to command prompt

[gentoo-user] Grub boots to command prompt

[Daniel D Jones]

Just did a stage 3 install following a HD crash on a new HD.  The initial 
install went without issue and I booted from the HD normally.  I then went 
through and installed a bunch of packages - xorg, kde, etc.  I installed 
genkernel, compiled a custom kernel, and updated /boot/grub/menu.lst.

Upon rebooting, I ended up at a grub command line.  I can setup the hard drive 
without errors:

grub> root (hd0,0)
 Filesystem type is ext2fs, partition type 0x83

grub> setup (hd0)
 Checking if "/boot/grub/stage1" exists... yes
 Checking if "/boot/grub/stage2" exists... yes
 Checking if "/boot/grub/e2fs_stage1_5" exists... yes
 Running "embed /boot/grub/e2fs_stage1_5 (hd0)"...  17 sectors are embedded.
succeeded
 Running "install /boot/grub/stage1 (hd0) (hd0)1+17 p (hd0,0)/boot/grub/stage2 
/boot/grub/menu.lst"... succeeded
Done.

No errors, says everything's good.  Reboot and I'm right back at the command 
line.

I can do

root (hd0,0)
kernel = /vmlinuz-blah
boot

and boot into the system, so I know the system and hd0,0 is bootable.  (I'm 
writing this message on it after doing the above.)

There are three hard drives in the system.  I've verified that the BIOS is set 
to boot from the first hard drive, which grub sees as hd0.  I've also, just to 
test it out, setup grub on hd1 and hd2, with hd0,0 set as root.  I still get 
the same thing.

Grub package version 0.97-r9 installed.  /boot is mounted to sda1, an ext2 
partition.  / is mounted to sda3, an ext3 partition.  

I'm not seeing any error messages on bootup or in grub.  I have no idea where 
to go with this and so far, web searches haven't been helpful.  Anyone have a 
clue?

-- 
"Governments are suspicious of literature because it is a force that eludes 
them." - Emile Zola

Re: [gentoo-user] Grub boots to command prompt

[Alan McKinnon]

On Thursday 24 December 2009 15:52:37 Daniel D Jones wrote:
> Just did a stage 3 install following a HD crash on a new HD.  The initial
> install went without issue and I booted from the HD normally.  I then went
> through and installed a bunch of packages - xorg, kde, etc.  I installed
> genkernel, compiled a custom kernel, and updated /boot/grub/menu.lst.
> 
> Upon rebooting, I ended up at a grub command line.  I can setup the hard
>  drive without errors:
> 
> grub> root (hd0,0)
>  Filesystem type is ext2fs, partition type 0x83
> 
> grub> setup (hd0)
>  Checking if "/boot/grub/stage1" exists... yes
>  Checking if "/boot/grub/stage2" exists... yes
>  Checking if "/boot/grub/e2fs_stage1_5" exists... yes
>  Running "embed /boot/grub/e2fs_stage1_5 (hd0)"...  17 sectors are
>  embedded. succeeded
>  Running "install /boot/grub/stage1 (hd0) (hd0)1+17 p
>  (hd0,0)/boot/grub/stage2 /boot/grub/menu.lst"... succeeded
> Done.
> 
> No errors, says everything's good.  Reboot and I'm right back at the
>  command line.
> 
> I can do
> 
> root (hd0,0)
> kernel = /vmlinuz-blah
> boot
> 
> and boot into the system, so I know the system and hd0,0 is bootable.  (I'm
> writing this message on it after doing the above.)
> 
> There are three hard drives in the system.  I've verified that the BIOS is
>  set to boot from the first hard drive, which grub sees as hd0.  I've also,
>  just to test it out, setup grub on hd1 and hd2, with hd0,0 set as root.  I
                                                        ^^^^^^^^^^^^^^^^^^
>  still get the same thing.

Your next paragraph indicates that (hd0,0) is not in fact root, but (what will 
eventually be) /boot.

Your root is likely to be (hd0,2)


> 
> Grub package version 0.97-r9 installed.  /boot is mounted to sda1, an ext2
> partition.  / is mounted to sda3, an ext3 partition.
> 
> I'm not seeing any error messages on bootup or in grub.  I have no idea
>  where to go with this and so far, web searches haven't been helpful. 
>  Anyone have a clue?
> 

-- 
alan dot mckinnon at gmail dot com

Re: [gentoo-user] Grub boots to command prompt

[Daniel D Jones]

On Thursday 24 December 2009 10:52:08 Alan McKinnon wrote:
> On Thursday 24 December 2009 15:52:37 Daniel D Jones wrote:
> > Just did a stage 3 install following a HD crash on a new HD.  The initial
> > install went without issue and I booted from the HD normally.  I then
> > went through and installed a bunch of packages - xorg, kde, etc.  I
> > installed genkernel, compiled a custom kernel, and updated
> > /boot/grub/menu.lst.
> >
> > Upon rebooting, I ended up at a grub command line.  I can setup the hard
> >  drive without errors:
> >
> > grub> root (hd0,0)
> >  Filesystem type is ext2fs, partition type 0x83
> >
> > grub> setup (hd0)
> >  Checking if "/boot/grub/stage1" exists... yes
> >  Checking if "/boot/grub/stage2" exists... yes
> >  Checking if "/boot/grub/e2fs_stage1_5" exists... yes
> >  Running "embed /boot/grub/e2fs_stage1_5 (hd0)"...  17 sectors are
> >  embedded. succeeded
> >  Running "install /boot/grub/stage1 (hd0) (hd0)1+17 p
> >  (hd0,0)/boot/grub/stage2 /boot/grub/menu.lst"... succeeded
> > Done.
> >
> > No errors, says everything's good.  Reboot and I'm right back at the
> >  command line.
> >
> > I can do
> >
> > root (hd0,0)
> > kernel = /vmlinuz-blah
> > boot
> >
> > and boot into the system, so I know the system and hd0,0 is bootable. 
> > (I'm writing this message on it after doing the above.)
> >
> > There are three hard drives in the system.  I've verified that the BIOS
> > is set to boot from the first hard drive, which grub sees as hd0.  I've
> > also, just to test it out, setup grub on hd1 and hd2, with hd0,0 set as
> > root.  I
> 
>                                                         ^^^^^^^^^^^^^^^^^^
> 
> >  still get the same thing.
> 
> Your next paragraph indicates that (hd0,0) is not in fact root, but (what
>  will eventually be) /boot.
> 
> Your root is likely to be (hd0,2)

Eh?  Your grub root should be where grub is installed, shouldn't it?  That's 
/dev/sda1 on my system, which grub sees as hd (0,0).  When the file system is 
mounted, that partition mounted under /boot but grub still needs to know where 
to find the menu.lst and various stage files on initial boot, and that's hd 
(0,0).

-- 
"Believe nothing, O monks, merely because you have been told it ... or because 
it is traditional, or because you yourselves have imagined it. Do not believe 
what your teacher tells you merely out of respect for the teacher. But 
whatsoever, after due examination and analysis, you find to be conducive to the 
good, the benefit, the welfare of all beings-that doctrine believe and cling 
to, and take it as your guide." - Gautama Buddha, Indian philosopher 
(536?-483? B.C.)

Re: [gentoo-user] Grub boots to command prompt

[Alan McKinnon]

On Thursday 24 December 2009 18:32:22 Daniel D Jones wrote:
> > Your next paragraph indicates that (hd0,0) is not in fact root, but (what
> >  will eventually be) /boot.
> > 
> > Your root is likely to be (hd0,2)
> 
> Eh?  Your grub root should be where grub is installed, shouldn't
>  it?  That's  /dev/sda1 on my system, which grub sees as hd (0,0).  When
>  the file system is mounted, that partition mounted under /boot but grub
>  still needs to know where to find the menu.lst and various stage files on
>  initial boot, and that's hd (0,0).
> 

grub doesn't have a concept of "root". It's a bootloader, not a OS, and 
doesn't mount anything. It just reads data directly off disk volumes and 
(sometimes) has drivers to interpret the raw data.

When you say "root" that can only make sense in the context of an OS that uses 
a "root", so I interpreted it as such.

grub is installed wherever you installed it. You can put it on any arbitrary 
drive you feel like, or even in the first sector of any arbitrary partition if 
the drive supports such. All you have to do is tell grub where it is.

Now, that introduces a wrinkle. On a PC, the BIOS does not support stage 1 
booting off a partition. The stage 1 code MUST exist on the MBR of a DRIVE 
(blame msdos for this stupid idea) so you want to install grub to /dev/sda or 
(hd0)

I strongly suspect that you are conflating the operation of a bootloader with 
the OS. At boot time Linux conventions have no relevance whatsoever and are 
not valid, as Linux is not running yet. grub Boots Linux, it is not Linux and 
does not work like Linux. Much the same way as a starter motor starts a petrol 
engine but a starter motor is not a petrol engine and does not work like one.


-- 
alan dot mckinnon at gmail dot com

Re: [gentoo-user] Grub boots to command prompt - solved

[Daniel D Jones]

On Thursday 24 December 2009 08:52:37 Daniel D Jones wrote:
> Just did a stage 3 install following a HD crash on a new HD.  The initial
> install went without issue and I booted from the HD normally.  I then went
> through and installed a bunch of packages - xorg, kde, etc.  I installed
> genkernel, compiled a custom kernel, and updated /boot/grub/menu.lst.
> 
> Upon rebooting, I ended up at a grub command line.  I can setup the hard
>  drive without errors:
> 
> grub> root (hd0,0)
>  Filesystem type is ext2fs, partition type 0x83
> 
> grub> setup (hd0)
>  Checking if "/boot/grub/stage1" exists... yes
>  Checking if "/boot/grub/stage2" exists... yes
>  Checking if "/boot/grub/e2fs_stage1_5" exists... yes
>  Running "embed /boot/grub/e2fs_stage1_5 (hd0)"...  17 sectors are
>  embedded. succeeded
>  Running "install /boot/grub/stage1 (hd0) (hd0)1+17 p
>  (hd0,0)/boot/grub/stage2 /boot/grub/menu.lst"... succeeded
> Done.
> 
> No errors, says everything's good.  Reboot and I'm right back at the
>  command line.

Found the issue.  For some reason, the default menu.lst created with the stage 
3 install had the title line commented out.  When I added the new genkernel to 
the file, I copied and pasted, then edited the kernel line.  My guess is that 
grub uses the title line as the flag to break between options.  With both title 
lines commented out, it saw a single option block with multiple kernel 
statements.  Uncommenting the title lines corrected the issue.

-- 
"The unnatural, that too is natural." - Goethe