bad magic number in superblock--system unusable.

[Old-Polack]

That's way different! Here's the output:
[root@localhost ~]# mount /dev/sda7 /mnt/here
[root@localhost ~]# cat /mnt/here/boot/grub/menu.lst
timeout 10
color black/cyan yellow/cyan
gfxmenu (hd0,8)/boot/gfxmenu
default 0

title linux
kernel (hd0,8)/boot/vmlinuz BOOT_IMAGE=linux root=UUID=170f21b3-6ea3-48c7-8c04-94bf0eba43dc quiet nokmsboot vmalloc=256M acpi=on resume=UUID=3c6ceea0-43e9-42ae-82d0-67ec3b17042b splash=silent vga=788
initrd (hd0,8)/boot/initrd.img

title linux-nonfb
kernel (hd0,8)/boot/vmlinuz BOOT_IMAGE=linux-nonfb root=UUID=170f21b3-6ea3-48c7-8c04-94bf0eba43dc quiet nokmsboot vmalloc=256M acpi=on resume=UUID=3c6ceea0-43e9-42ae-82d0-67ec3b17042b
initrd (hd0,8)/boot/initrd.img

title failsafe
kernel (hd0,8)/boot/vmlinuz BOOT_IMAGE=failsafe root=UUID=170f21b3-6ea3-48c7-8c04-94bf0eba43dc quiet nokmsboot failsafe vmalloc=256M acpi=on
initrd (hd0,8)/boot/initrd.img

title windows
root (hd0,0)
makeactive
chainloader +1

title memtest-4.20
kernel (hd0,8)/boot/memtest-4.20 BOOT_IMAGE=memtest-4.20

title           Linux Mint 14 Nadia (14) (on /dev/sda5)
root            (hd0,4)
kernel          /boot/vmlinuz-3.5.0-17-generic root=/dev/sda5
initrd          /boot/initrd.img-3.5.0-17-generic
savedefault
boot


title 3.2.18-pclos2.pae.bfs
kernel (hd0,8)/boot/vmlinuz-3.2.18-pclos2.pae.bfs BOOT_IMAGE=3.2.18-pclos2.pae.bfs root=UUID=170f21b3-6ea3-48c7-8c04-94bf0eba43dc quiet nokmsboot vmalloc=256M acpi=on resume=UUID=3c6ceea0-43e9-42ae-82d0-67ec3b17042b splash=silent vga=788
initrd (hd0,8)/boot/initrd-3.2.18-pclos2.pae.bfs.img

# This is a divider, added to separate the menu items below from the PCLINUXOS standard grub entries
title           Other operating systems:


# This entry automatically added by the PCLinuxOS redo-mbr for an existing
# linux installation on /dev/sda5.
title           Linux Mint 14 Nadia (14) (on /dev/sda5)
root            (hd0,4)
kernel          /boot/vmlinuz-3.5.0-17-generic root=/dev/sda5
initrd          /boot/initrd.img-3.5.0-17-generic
savedefault
boot


# This is a divider, added to separate the menu items below from the PCLINUXOS standard grub entries
title           Other operating systems:


# This entry automatically added by the PCLinuxOS redo-mbr for an existing
# linux installation on /dev/sda13.
title           PCLinuxOs_64 (on /dev/sda13)
root            (hd0,12)
kernel          /boot/vmlinuz BOOT_IMAGE=PCLinuxOs_64 root=UUID=50367372-b1c6-4dff-a774-4a3129954fca quiet nokmsboot vmalloc=256M acpi=on resume=UUID=3c6ceea0-43e9-42ae-82d0-67ec3b17042b splash=silent vga=788
initrd          (hd0,12)/boot/initrd.img
savedefault
boot


# This entry automatically added by the PCLinuxOS redo-mbr for an existing
# linux installation on /dev/sda5.
title           Linux Mint 14 Nadia (14) (on /dev/sda5)
root            (hd0,4)
kernel          /boot/vmlinuz-3.5.0-17-generic root=/dev/sda5
initrd          /boot/initrd.img-3.5.0-17-generic
savedefault
boot


# This is a divider, added to separate the menu items below from the PCLINUXOStandard grub entries
title           Other operating systems:


# This entry automatically added by the PCLinuxOS redo-mbr for an existing
# linux installation on /dev/sda12.
title           PCLinuxOs_64 (on /dev/sda12)
root            (hd0,11)
kernel          /boot/vmlinuz BOOT_IMAGE=PCLinuxOs_64 root=UUID=50367372-b1c6-ff-a774-4a3129954fca quiet nokmsboot vmalloc=256M acpi=on resume=UUID=3c6ceea03e9-42ae-82d0-67ec3b17042b splash=silent vga=788
initrd          (hd0,12)/boot/initrd.img
savedefault
boot


# This entry automatically added by the PCLinuxOS redo-mbr for an existing
# linux installation on /dev/sda5.
title           Linux Mint 14 Nadia (14) (on /dev/sda5)
root            (hd0,4)
kernel          /boot/vmlinuz-3.5.0-17-generic root=/dev/sda5
initrd          /boot/initrd.img-3.5.0-17-generic
savedefault
boot


I don't know if you groked the partitions I think are the present homes of pclos systems:
sda7: 32 /
sda8: /home (for both 32 and 64)
sda11: 64 /
(I believe sda5 is Mint 64)

--doug

Next step...

[root@localhost ~]# kwrite /mnt/here/boot/grub/menu.lst                    <Enter>

When kwrite opens, each of the 8s above needs to be changed to a 6. Save the file, close kwrite, then do the following;

[root@localhost ~]# grub                              <Enter>
Probing devices to guess BIOS drives. This may take a long time.


    GNU GRUB  version 0.97  (640K lower / 3072K upper memory)

 [ Minimal BASH-like line editing is supported.  For the first word, TAB
   lists possible command completions.  Anywhere else TAB lists the possible
   completions of a device/filename. ]
grub> root (hd0,6)
root (hd0,6)
 Filesystem type is ext2fs, partition type 0x83
grub> setup (hd0)
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 (hd0,6)/boot/grub/stage2 /boot/grub/menu.lst"... succeeded
Done.
grub> quit
quit
[root@localhost ~]#

You should then be able to boot to the 32bit installation. Once that is accomplished, we can then do more edits to boot the 64bit installations.

[dougmack]

When the system says this may take a long time, how much time are we talking about?
At this point,
 [ Minimal BASH-like line editing is supported.  For the first word, TAB
   lists possible command completions.  Anywhere else TAB lists the possible
   completions of a device/filename. ]
grub> root (hd0,6)

It's sitting there for 30 minutes waiting for "root (hd0,6)"--is that reasonable?
I can go to bed and see if it's done in the morning, but this is a l o o o o n g time!
I believe I got all the hd0,8 changed to hd0,6--I counted 10 instances. I am assuming
you did not mean to change the 8s in the hex code lines.

--doug

[Old-Polack]

When the system says this may take a long time, how much time are we talking about?
At this point,
 [ Minimal BASH-like line editing is supported.  For the first word, TAB
   lists possible command completions.  Anywhere else TAB lists the possible
   completions of a device/filename. ]
grub> root (hd0,6)

It's sitting there for 30 minutes waiting for "root (hd0,6)"--is that reasonable?
I can go to bed and see if it's done in the morning, but this is a l o o o o n g time!
I believe I got all the hd0,8 changed to hd0,6--I counted 10 instances. I am assuming
you did not mean to change the 8s in the hex code lines.

--doug

If it hasn't shown up in a couple of minutes, something is seriously wrong. Close that terminal, then open a fresh one. Again we'll try grub;

[root@localhost ~]# grub
Probing devices to guess BIOS drives. This may take a long time.


    GNU GRUB  version 0.97  (640K lower / 3072K upper memory)

 [ Minimal BASH-like line editing is supported.  For the first word, TAB
   lists possible command completions.  Anywhere else TAB lists the possible
   completions of a device/filename. ]
grub> find /boot/grub/stage2
find /boot/grub/stage2
 (hd0,0)
 (hd0,5)
 (hd0,6)                                       <-- I have a lot of installations. You should have fewer results.
 (hd1,0)
 (hd1,2)
 (hd2,0)
 (hd2,2)
 (hd2,4)
 (hd2,5)
 (hd2,6)
 (hd2,8)
 (hd2,9)
 (hd2,10)
 (hd2,14)
 (hd2,15)
grub>

Post your results up to this point.

[dougmack]

There are no results. After the "grub>" line, there is nothing. Was I supposed to type in
" find /boot/grub/stage2" ? I thought the computer was supposed to generate that line.
I'm sorry if I misunderstood. (I'm trying to be careful so as not to make a bad situation even worse.)
--doug

[kjpetrie]

Every time you see the grub> prompt that is where you type the next instruction.

[dougmack]

OK, I only see the grub prompt (grub>) if I type in grub. Then if I type in the words in color,
I get

(hd0,6)
(hd0,10)
grub>

and then if I type in the words in color again, I get the same thing. Here's a copy of the terminal:
[root@localhost grub]# grub
Probing devices to guess BIOS drives. This may take a long time.


    GNU GRUB  version 0.97  (640K lower / 3072K upper memory)

 [ Minimal BASH-like line editing is supported.  For the first word, TAB
   lists possible command completions.  Anywhere else TAB lists the possible
   completions of a device/filename. ]
grub> find /boot/grub/stage2
find /boot/grub/stage2
 (hd0,6)
 (hd0,10)
grub> find /boot/grub/stage2
find /boot/grub/stage2
 (hd0,6)
 (hd0,10)

This is the output no matter how often I type in "find /boot/grub/stage2"
after the grub> prompt.

--doug

[Old-Polack]

OK, I only see the grub prompt (grub>) if I type in grub. Then if I type in the words in color,
I get

(hd0,6)
(hd0,10)
grub>

and then if I type in the words in color again, I get the same thing. Here's a copy of the terminal:
[root@localhost grub]# grub
Probing devices to guess BIOS drives. This may take a long time.


    GNU GRUB  version 0.97  (640K lower / 3072K upper memory)

 [ Minimal BASH-like line editing is supported.  For the first word, TAB
   lists possible command completions.  Anywhere else TAB lists the possible
   completions of a device/filename. ]
grub> find /boot/grub/stage2
find /boot/grub/stage2
 (hd0,6)
 (hd0,10)
grub> find /boot/grub/stage2
find /boot/grub/stage2
 (hd0,6)
 (hd0,10)

This is the output no matter how often I type in "find /boot/grub/stage2"
after the grub> prompt.

--doug

Next command would be

grub> root (hd0,6)                                     <Enter>

followed by

grub> setup (hd0)                                    <Enter>

Post your results.

[dougmack]

Ok, here:

grub> root (hd0,6)
root (hd0,6)
 Filesystem type is ext2fs, partition type 0x83
grub> setup (hd0)
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 (hd0,6)/boot/grub/stage2 /boot/grub/menu.lst"... succeeded
Done.

[Old-Polack]

Ok, here:

grub> root (hd0,6)
root (hd0,6)
 Filesystem type is ext2fs, partition type 0x83
grub> setup (hd0)
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 (hd0,6)/boot/grub/stage2 /boot/grub/menu.lst"... succeeded
Done.

Next command:

grub> quit                                           <Enter>

You should now be back at the normal prompt.

Try a reboot to the installed 32 bit system.

[dougmack]

Replying from my 32-bit system! It is working just the way it always did! The boot screen showed a long list of possible chouces, but
I haven't tried any of them, not wanting to bollix things up at this point!
Thank you!
What do I have to do next?

--doug

[kjpetrie]

In /boot/grub/menu.lst, change all references to sda13 to sda11 and all (hd0,12) to (hd0,10).

That should enable you to boot into the first 64-bit as well.

Is the other 64-bit stanza a third pclos install or a confused error (its kernel and initrd locations don't agree so it's definitely in error at the moment)?

[dougmack]

There was only one pclos-64 installation. I have been looking at the menu.lst, and it looks like there are a few things that could be removed.
Before I do that and screw up again, I would like confirmation, please.
I have numbered the stanzas that start with the word "title"--I count 12.  If I am correct, I could delete numbers 7,8,10, 11, and 12.
Is this correct?
I would like to get rid of the chaff, since it takes quite a while to boot either the -32 or the -64, and I surmise that the machine is perusing
the extra stanzas before deciding to ignore them.
I haven't tried the Mint boot, but I expect it is OK, since partition sda5 was never moved. (I will do so, and report if anything is wrong there.
I don't usually use Mint for anything, but it's interesting.)

Thanx once again to all who have contributed to pulling me out of a big hole!

--doug

[kjpetrie]

The machine peruses the stanzas only for as long as it takes to display them, which is microseconds or milliseconds at most. Only the stanza you select gets passed to grub stage 2, which loads the kernel and passes it all the other info it contains. The kernel does the rest.

So the delay won't be caused by the number of stanzas. That's more likely to be a lost swap partition being waited for so the kernel can check whether it's a new boot or a return from suspension. After about a minute it times out and carries on with a new boot if that's the cause.

I would tend to keep 7, but delete 8, 10, 11 and 12. Sometimes a stanza that boots directly to the kernel can be useful if something (like a botched upgrade) corrupts the symbolic links in /boot.

[dougmack]

The three Linuxs work. Windows won't boot. The cellar window shows, then the little dingus goes around a few times, then nothing.
I have downloaded a disk that's supposed to boot Windows 8--it will probably screw up the boot sector. Will a live CD and "redo MBR fix that?

--doug