Grub

Fixing grub on Ubuntu (from live CD)

sudo fdisk -l

sudo mount /dev/sda1 /mnt

sudo mount --bind /dev /mnt/dev

sudo mount --bind /proc /mnt/proc

sudo mount --bind /sys /mnt/sys

sudo chroot /mnt

grub-mkconfig -o /boot/grub/grub.cfg

grub-install /dev/sda (try grub-install --recheck /dev/sda if it fails)

grub-install /dev/sda1 --force (should be ok despite the warning)

Ctrl+D (to exit out of chroot)

sudo umount /mnt/dev

sudo umount /mnt/proc

sudo umount /mnt/sys

sudo umount /mnt

Over RAID

When running a software RAID 1, you want to have grub installed over both boot disks (in case one fails)

[root@fedora4 ~]# grub

GNU GRUB version 0.95 (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 (hd0,0)

Filesystem type is ext2fs, partition type 0xfd

grub> 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)"... 15 sectors are embedded.

succeeded

Running "install /boot/grub/stage1 (hd0) (hd0)1+15 p (hd0,0)/boot/grub/stage2

/boot/grub/grub.conf"... succeeded

Done.

grub> root (hd1,0)

Filesystem type is ext2fs, partition type 0xfd

grub> setup (hd1)

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 (hd1)"... 15 sectors are embedded. succeeded Running "install /boot/grub/stage1 (hd1) (hd1)1+15 p (hd1,0)/boot/grub/stage2 /boot/grub/grub.conf"... succeeded Done.

grub> quit