Unable to umount a partition

I created a partition with some EASUES Partition maneger from windows of the remaining space i had. Shortly after i ran into boot failiure Grub error 17…
I corrected it usin the openSUSE cd. When i did an auto repair it checked my fstab and detected my new partition

/dev/sda8

it created some mount point in some folder created called data6 in the root.

When i now booted it /dev/sda8 is mounted to / while my actual linux partition is /dev/sda13… I can’t unmount it format or edit. WHat should i do…
The problem is that the fstab actually points sda8 to mount it somewhere else. here is my fstab…

/dev/disk/by-id/scsi-SATA_ST3160215AS_6RA3XAHN-part13 / ext3 acl,user_xattr 1 1
/dev/disk/by-id/scsi-SATA_ST3160215AS_6RA3XAHN-part1 /windows/C vfat users,gid=users,umask=0002,utf8=true 0 0
/dev/disk/by-id/scsi-SATA_ST3160215AS_6RA3XAHN-part6 /windows/E vfat users,gid=users,umask=0002,utf8=true 0 0
sysfs /sys sysfs noauto 0 0
debugfs /sys/kernel/debug debugfs noauto 0 0
usbfs /proc/bus/usb usbfs noauto 0 0
devpts /dev/pts devpts mode=0620,gid=5 0 0
/dev/sda5 /windows/D ntfs-3g users,gid=users,fmask=133,dmask=022,locale=en_US.UTF-8 0 0
/dev/sda7 swap ntfs-3g users,gid=users,fmask=133,dmask=022,locale=en_US.UTF-8 0 0
/dev/sda8 /windows/G ntfs-3g users,gid=users,fmask=133,dmask=022,locale=en_US.UTF-8 0 0

This has not much to do with your fstab. / is mounted much earlier in the boot process. Just think of the fact that /etc/fstab can only be read by the system when / is mounted allready. So you can not repair this by changing something in the fstab.

Also you can not umount a partition that is in use and of course the / partition is always in use on a running system.

I wonder which system is running at the moment? Beacuse you have something running when you state that you can not umount …

I should also look in /boot/grub/menu.lst because there is a root= parameter that tells the boot ystem where the / partition is. You may post the contents here to get more help.