redhat will not boot, boot to grub prompt

Discussion:

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trevor

2005-01-04 21:00:19 UTC

my redhat 9 will not boot. We had a power failure and when the power
came back, my redhat linux will not boot.

The machine come up to grub prompt.

I tried the following from grub prompt

root (hd0, then press tab key

partition num:0 filesystem type unknown, partition type 0x83
partition num:1 filesystem type is ext2fs, partition type 0x83
partition num:2 filesystem type is ext2fs, partition type 0x83
partition num:3 filesystem type is ext2fs, partition type 0x83
partition num:4 filesystem type is ext2fs, partition type 0x83
partition num:5 filesystem type is ext2fs, partition type 0x83
partition num:6 filesystem type unknown, partition type 0x83
partition num:7 filesystem type is ext2fs, partition type 0x83
partition num:8 filesystem type is ext2fs, partition type 0x83

my boot partition is on 0
so I issued root (hd0,0)

received the error message filesystem type unknown, partition type
0x83

setup (hd0)
checking if /boot/grub/stage1 exist ... no
checking if /grub/stage1 exist ...no

Also try

configfile /boot/grub/grub.conf
Error 15: file not found

configfile /grub/grub.conf
Error 15: file not found

grub> find /boot/vmlinuz
Error 15: file not found

grub> find /boot/initrd.gz
Error 15: file not found

Finally, I tried copy stage1 file and stage2 from an identical machine
to floppy disk then

grub>root (fd0)
error filesystem type unknown, using whole disk
grub>setup (fd0)
error 17, cannot mount selected parttion
grub>quit

can you help, please.

delcielo

2005-01-05 21:52:13 UTC

Permalink

It probably needs an fsck, if not more; but for starters...

Using a RedHat 9 boot disk, enter "linux rescue" at the "boot" prompt.

Follow the onscreen instructions to get your machine to a command
prompt. It will say things like "installation"; but it's really just
starting the rescue environment.

It will try to mount your filesystems under /mnt/sysimage ; but will
likely be unable to mount your /dev/hda0 partition. If it IS able to
do so, unmount it.

Enter "fsck -y /dev/hda0" at the command prompt to run the file-system
checker against your boot partition.

At this point, you can try rebooting; but I suspect you might still
have issues. If you do, enter rescue mode again and at the command
prompt:

Mount the /dev/hda0 partition if it's not already mounted by making a
directory to mount it on (i.e. /mnt/sysimage/boot) and issuing "mount
-t ext3 /dev/hda0 /mnt/sysimage/boot"

"cd /mnt/sysimage/boot"

"chroot /mnt/sysimage"

"grub-install /dev/hda"

That will rewrite your boot sector.

You should be able to reboot then.

Good luck,
Chris

Post by trevor
my redhat 9 will not boot. We had a power failure and when the power
came back, my redhat linux will not boot.
The machine come up to grub prompt.
I tried the following from grub prompt
root (hd0, then press tab key
partition num:0 filesystem type unknown, partition type 0x83
partition num:1 filesystem type is ext2fs, partition type 0x83
partition num:2 filesystem type is ext2fs, partition type 0x83
partition num:3 filesystem type is ext2fs, partition type 0x83
partition num:4 filesystem type is ext2fs, partition type 0x83
partition num:5 filesystem type is ext2fs, partition type 0x83
partition num:6 filesystem type unknown, partition type 0x83
partition num:7 filesystem type is ext2fs, partition type 0x83
partition num:8 filesystem type is ext2fs, partition type 0x83
my boot partition is on 0
so I issued root (hd0,0)
received the error message filesystem type unknown, partition type
0x83
setup (hd0)
checking if /boot/grub/stage1 exist ... no
checking if /grub/stage1 exist ...no
Also try
configfile /boot/grub/grub.conf
Error 15: file not found
configfile /grub/grub.conf
Error 15: file not found
grub> find /boot/vmlinuz
Error 15: file not found
grub> find /boot/initrd.gz
Error 15: file not found
Finally, I tried copy stage1 file and stage2 from an identical

machine

Post by trevor
to floppy disk then
grub>root (fd0)
error filesystem type unknown, using whole disk
grub>setup (fd0)
error 17, cannot mount selected parttion
grub>quit
can you help, please.

m.marien

2005-01-06 14:26:30 UTC

Permalink

Post by delcielo
It probably needs an fsck, if not more; but for starters...
Using a RedHat 9 boot disk, enter "linux rescue" at the "boot" prompt.
Follow the onscreen instructions to get your machine to a command
prompt. It will say things like "installation"; but it's really just
starting the rescue environment.
It will try to mount your filesystems under /mnt/sysimage ; but will
likely be unable to mount your /dev/hda0 partition. If it IS able to
do so, unmount it.

These should all be /dev/hda1 - not /dev/hda0. Grub uses zero as the first
partition, but linux uses one.

Are you sure that the first partition was the boot partition. It may be
swap. I would boot from the CD and do a linux rescue as Chris has described.
Let it find your root and just check /mnt/sysimage/boot to see if there are
any files in there.

If there are then your procedure or Chris's will work, but use root (hd0,1)
setup (hd0). If there are no files then check the /mnt/sysimage/etc/mtab to
see which partition is the boot partition. If you can't restore it with
fsck, then do an update with the RH9 CD. It should restore all the files
keeping the configure and any data files. It should also leave any software
that you have upgraded yourself or that were upgraded with up2date.

Post by delcielo
Enter "fsck -y /dev/hda0" at the command prompt to run the file-system
checker against your boot partition.
At this point, you can try rebooting; but I suspect you might still
have issues. If you do, enter rescue mode again and at the command
Mount the /dev/hda0 partition if it's not already mounted by making a
directory to mount it on (i.e. /mnt/sysimage/boot) and issuing "mount
-t ext3 /dev/hda0 /mnt/sysimage/boot"
"cd /mnt/sysimage/boot"
"chroot /mnt/sysimage"
"grub-install /dev/hda"
That will rewrite your boot sector.
You should be able to reboot then.
Good luck,
Chris

machine

Post by trevor
to floppy disk then
grub>root (fd0)
error filesystem type unknown, using whole disk
grub>setup (fd0)
error 17, cannot mount selected parttion
grub>quit
can you help, please.