grub error 18.

epsonik · #1 19th June 2011, 01:07 PM

Hi, after installing FC15 on my computer, I cannot boot on my windows7 due to an error 18.

I installed FC on 2 new partitions I created during the installation, so I guess they moved before my window's...

Is there a solution to fix this without erasing my windows partition? (at worse, I'm ok with deleting my linux partitions for I haven't done anything with it yet)

at worse, will just deleting my newly created linux partitions help recover things?

thx.

stoat · #2 19th June 2011, 02:05 PM

I don't know if there is a solution or not. But a good and usual place to start is to post something for people to look at and think about. Open a terminal window in Fedora and run the following commands. Then copy it here. Maybe somebody will see something to adjust....

Code:

su
fdisk -l
cat /boot/grub/grub.conf

If you never get anywhere with GRUB, you can consider restoring the Windows boot loader so it boots again directly from BIOS. Then use the free and popular software known as EasyBCD to configure the Windows boot loader to boot Fedora.

epsonik · #3 19th June 2011, 02:14 PM

ok

here's my fdisk result:

Code:

Disque /dev/sda*: 1500.3*Go, 1500301910016 octets
255 têtes, 63 secteurs/piste, 182401 cylindres, total 2930277168 secteurs
Unités = secteurs de 1 * 512 = 512 octets
Taille de secteur (logique / physique)*: 512*octets / 512*octets
taille d'E/S (minimale / optimale)*: 512*octets / 512*octets
Identifiant de disque*: 0x29d73382

Périphérique Amorce  Début        Fin      Blocs     Id  Système
/dev/sda1           16065  2848356629  1424170282+   f  Étendue W95 (LBA)
/dev/sda2   *  2848356630  2930255999    40949685    7  HPFS/NTFS/exFAT
/dev/sda5       102430503  1516359284   706964391    7  HPFS/NTFS/exFAT
/dev/sda6      1516359348  2848356629   665998641    7  HPFS/NTFS/exFAT
/dev/sda7           18432    92178431    46080000   83  Linux
/dev/sda8        92180480   102428671     5124096   82  partition d'échange Linux / Solaris

Les entrées de la table de partitions ne sont pas dans l'ordre du disque

Disque /dev/sdb*: 500.1*Go, 500107862016 octets
255 têtes, 63 secteurs/piste, 60801 cylindres, total 976773168 secteurs
Unités = secteurs de 1 * 512 = 512 octets
Taille de secteur (logique / physique)*: 512*octets / 512*octets
taille d'E/S (minimale / optimale)*: 512*octets / 512*octets
Identifiant de disque*: 0x059a059a

Périphérique Amorce  Début        Fin      Blocs     Id  Système
/dev/sdb1              63    30716279    15358108+   7  HPFS/NTFS/exFAT
/dev/sdb2        30716280   976751999   473017860    f  Étendue W95 (LBA)
/dev/sdb5        30716343   935786249   452534953+   7  HPFS/NTFS/exFAT
/dev/sdb6       935788544   976750591    20481024   83  Linux

and here's my grub file (I didn't edit this one yet):

Code:

# grub.conf generated by anaconda
#
# Note that you do not have to rerun grub after making changes to this file
# NOTICE:  You do not have a /boot partition.  This means that
#          all kernel and initrd paths are relative to /, eg.
#          root (hd0,6)
#          kernel /boot/vmlinuz-version ro root=/dev/sda7
#          initrd /boot/initrd-[generic-]version.img
#boot=/dev/sda
default=1
timeout=5
splashimage=(hd0,6)/boot/grub/splash.xpm.gz
hiddenmenu
title Fedora (2.6.38.8-32.fc15.x86_64)
	root (hd0,6)
	kernel /boot/vmlinuz-2.6.38.8-32.fc15.x86_64 ro root=UUID=c876718f-e5ed-4042-a68d-cc288fe69714 rd_NO_LUKS rd_NO_LVM rd_NO_MD rd_NO_DM LANG=fr_FR.UTF-8 SYSFONT=latarcyrheb-sun16 KEYTABLE=fr-latin9 rhgb quiet
	initrd /boot/initramfs-2.6.38.8-32.fc15.x86_64.img
title Windows 7
	rootnoverify (hd0,1)
	chainloader +1

stoat · #4 19th June 2011, 02:51 PM

Looking at the first drive in sector order, after some empty sectors at the front end of the drive, a large extended partition begins. The first logical partition in the extended partition is the Fedora root partition. Next is a swap partition. Then two more NTFS logical partitions follow and finish filling the extended partition. Then following the extended partition, at the very back end of the hard drive, is the active NTFS partition which apparently is the Windows partition. So you may have some trouble booting that with GRUB because of the distant (from the beginning) sectors it occupies. The grub.conf file looks okay to me. I don't have a suggestion for it. Sorry. Maybe somebody else knows of something to try.

You can consider the EasyBCD idea as already mentioned.

You can try restoring the Windows boot loader if for no other reason than to confirm that Windows stills works. After all, there are some empty sectors at the beginning of the drive. Could a Windows 7 boot partition have been there?

epsonik · #5 19th June 2011, 04:34 PM

yup, that's a win7.

I'll look into EasyBCD then, thx, I'll come back if I have more questions for you guys

[edit]
Hmm, seems fairly complicated to get that working under fedora, so I guess I'll just restore the windows bootloader for the moment, I'll pass by later if I have any problem with EasyBCD, thx

[/edit]

---------- Post added at 05:34 PM ---------- Previous post was at 04:50 PM ----------

tiens d'ailleur dans ce cas, il faut que j'utilise l'option /FixMBR ou /FixBoot ??

stoat · #6 19th June 2011, 04:44 PM

Try Bootrec.exe /FixMbr first and reboot. See if Windows boots again. That removes GRUB from the master boot record and replaces it with MS boot code which works by finding the active partition and executing its boot sector code. The boot sector of the Windows partition should remain in good condition. If the Windows boot loader files are in that partition's filesystem, then Windows should boot again after the FixMbr option. The FixBoot option of the command rewrites boot sector code in the partition with the Windows boot loader files. I don't think it's necessary for this situation, but it shouldn't hurt to run that even when it's not necessary.