Re: GRUB Loading Stage2Read Error
From: Enrique Perez-Terron (enrio_at_online.no)
Date: 11/29/05
- Previous message: Enrique Perez-Terron: "Re: Grub hangs - two hard drives and a CD"
- In reply to: alan: "GRUB Loading Stage2Read Error"
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Date: Tue, 29 Nov 2005 19:47:40 +0100
On Tue, 29 Nov 2005 07:05:08 +0100, alan <misc@alanroter.com> wrote:
> I'm having trouble booting a new install of Fedora Core 4 running on a
> home-built system with an AMD Athlon 64-bit Processor 3000 with 1Gb RAM
> using an Abit NV8-V motherboard and two IDE drives plus DVD, etc. Its a
> pretty standard system.
>
> At boot time, the system reads from the master drive (/dev/hda) and
> gives an error "GRUB Loading stage2Read Error".
Seems alarming, because it looks like it fails during the load of stage2.
The problem I point at below with grub.conf should only affect what happens
after stage2 is loaded.
[...]
> The /boot partition contains the kernel and the /boot/grub directory
> with all of the grub files. The grub.conf file looks like this:
>
> # grub.conf generated by anaconda
> #
> # Note that you do not have to rerun grub after making changes to this
> file
> # NOTICE: You have a /boot partition. This means that
> # all kernel and initrd paths are relative to /boot/, eg.
> # root (hd0,0)
> # kernel /vmlinuz-version ro root=/dev/hda2
> # initrd /initrd-version.img
> #boot=/dev/hda1
> default=1
^^^^^^^^^^
Numbering starts at zero. With only one stanza below, there is no default one.
I don't know if this explains the error message you get, but I would try to
put "default=0" and see if it makes a difference.
> timeout=5
> splashimage=(hd0,0)/grub/splash.xpm.gz
> hiddenmenu
> title Fedora Core (2.6.11-1.1369_FC4)
> root (hd0,0)
> kernel /vmlinuz-2.6.11-1.1369_FC4 ro root=LABEL=/ rhgb quiet
> initrd /initrd-2.6.11-1.1369_FC4.img
>
> Again, this all looks quite standard, but the system does not boot up
> and stops at the "GRUB Loading stage2Read Error".
>
> So reading this group and looking for anything related to grub errors
> on the net, I've tried a number of things, still with no success:
>
> 1) I'm booting off the FC4 rescue CD, mounting the hda partitions and
> chroot'ing /mnt/sysimage to get my hda partitions online.
>
> 2) In grub (GNU GRUB 0.95), I've done the following:
>
> sh-3.00# grub
> grub> find /grub/stage2
> find /grub/stage2
> (hd0,0)
> grub> root (hd0,0)
> root (hd0,0)
> Filesystem type is ext2fs, partition type 0x83
> grub> kernel /vmlinuz-2.6.11-1.1369_FC4 ro root=/dev/hda2
> kernel /vmlinuz-2.6.11-1.1369_FC4 ro root=/dev/hda2
> [Linux-bzImage, setup=0x1e00, size=0x1da85c1
> grub> initrd /initrd-2.6.11-1.1369_FC4.img
> initrd /initrd-2.6.11-1.1369_FC4.img
>
> Error 28: Selected item cannot fit into memory
> grub> boot
> boot
> sh-3.00#
It does not work to boot from grub when grub is running under a kernel.
The only purpose of running grub under Linux, is to issue "setup" commands.
(Which is what grub-install does for you.)
> which bounces me back to the shell prompt without a reboot. I've seen
> some info on the web dating back to RedHat 8.0 in 2002 that suggested
> there was a hardware incompatibility that was causing this. Could this
> still be the case?
The error message is of course silly, but the overall behavior is
perfectly expected.
> The sizes for the kernel and initrd files are 1,951,836 and 1,303,392,
> respectively, so it is not clear that this error message is accurate
> with 1Gb of RAM. I saw a note about limited RAM-disk space on one
> posting, but I don't believe I am using one nor did I understand the
> issue, but it is possible that the rescue CD is setting up a RAM-disk
> and that is memory limited?
No, what happens is that when running under Linux, the program allocates
about 100 000 bytes in order to *simulate* the boot environment. This is
of course not enough to load a kernel and an initrd.
> 3) I've also tried grub-install:
>
> sh-3.00# grub-install --recheck /dev/hda
Looks correct to me.
> Probing devices to guess BIOS drives. This may take a long time.
> Installation finished. No error reported.
> This is the contents of the device map /boot/grub/device.map;.
> check if this is correct or not. If any of the lines is incorrect,
> fix it and re-run the script 'grub-install'.
>
> (fd0) /dev/fd0
> (hd0) /dev/hda
> (hd1) /dev/hdb
>
> sh-3.00# vi /boot/grub/device.map
> [deleted fd0 and hdb lines, saved]
OK, but should not make any difference.
> sh-3.00# grub-install /dev/hda
> Installation finished. No error reported.
> This is the contents of the device map /boot/grub/device.map;.
> check if this is correct or not. If any of the lines is incorrect,
> fix it and re-run the script 'grub-install'.
>
> (hd0) /dev/hda
> sh-3.00#
>
> 4) Finally, I've set the BIOS to boot off the hda drive first. I've
> checked and DMA is enabled. I haven't tried booting from a "grub boot
> floppy" but I think the Fedora rescue CD is allowing me to do something
> similar.
>
>
> After all of the above, I remove the rescue CD and reboot, and the
> machine stops at "GRUB Loading stage2Read Error".
The feeling I have is that something is going wrong during grub-install,
and I wonder if the fact that you are running grub-install under a chroot
environment could trigger a bug in grub.
Grub-install tries to find out if you have a separate /boot partition,
and what partition holds your root file system. For this it uses the "df"
command. "df" uses /etc/mntab, but when running under a chroot, "df" does
not have access to a valid /etc/mtab, and might get confused by that.
Do you have a floppy drive on your computer? No? Argh, when the world for
once goes forward and drops that unreliable beast, then you need it.
(If you can boot off a floppy, copy the files /usr/share/grub/*/stage[12]
to a floppy (obs obs obs don't copy them as files into a fat-formatted
msdos floppy, copy them to a raw floppy block device, eg.
cd /usr/share/grub/*
cat stage1 stage2 > /dev/fd0
then boot off the floppy. You get a grub prompt, which permits you to
Grub> find /grub/stage2
(hd0,0)/grub/stage2
Grub> root (hd0,0)
Grub> setup (hd0)
take out the floppy and any cdrom, and reboot.)
Not having a floppy, try to run grub without chroot.
Check if you have grub-install and grub in your path on the rescue cd
sh-3.00# type grub
grub is /sbin/grub
sh-3.00# type grub-install
grub is /sbin/grub-install
If you don't have it, add the sysimage directories to the path:
sh-3.00# PATH="$PATH:/mnt/sysimage/sbin:/mnt/sysimage/bin"
Run grub-install with the --debug option, to see what it ends up
doing. You probably also need to use the --root-dir option since you
are running from a CD.
sh-3.00# grub-install --debug --root-dir=/mnt/sysimage /dev/hda
You should see it assign values to "grubdir" and to "grub_prefix", and there
should be a call to "install_boot_block (hd0,0) (hd0)".
If this went well, you should now be able to boot your new system.
If not, a last attempt: from the rescue cd, run grub's setup command
directly:
sh-3.00# grub
grub> root (hd0,0)
grub> setup --stage2=/grub/stage2 --prefix=/grub (hd0)
grub> quit
Again, you should now be able to reboot.
-Enrique
- Previous message: Enrique Perez-Terron: "Re: Grub hangs - two hard drives and a CD"
- In reply to: alan: "GRUB Loading Stage2Read Error"
- Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]
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