Linux on GRUB Prompt

[zulqarnainhabib]

Hi

I have a machine running Centos 6.2 32 bit with two harddisks with RAID-1. First partition is /boot. Second is LVM for /home and Swap.

It was running fine until I ran yum update and the machine was powered off in the middle. Now when the machine starts, it directly comes to GRUB prompt. I don't know what to do know.

When I type boot at the prompt it says: Error : Kernel must be loaded before booting

I tried several blogs through google and did what they suggested but no luck. E.g.

grub> find /boot/grub/menu.lst
find /boot/grub/menu.lst

Error 15: File not found
grub> find /sbin/init
find /sbin/init

Error 15: File not found



grub> root (hd0,0)
root (hd0,0)
Filesystem type unknown, partition type 0xfd


This is not a production machine. I can easily re-install that but I want to recover and learn troubleshooting with that. Any help will be much appreciated.

Zulqarnain

[glennzo]

I'm not familiar with raid at all other than some basic reading about what raid is. Having said that, I'm probably better off not replying at all.

If there is a file not found error then my first thought would be to start by checking the disks / raid setup. Maybe you could use a live cd and access the disks from the command line?

Doesn't power off, like pulling the plug, damage raid setups?

[zulqarnainhabib]

I started the machine in Rescue mode and did chroot /mnt/sysimage. Here is the output of fdisk -l:

root@localhost ~]# fdisk -l

Disk /dev/sda: 8589 MB, 8589934592 bytes
255 heads, 63 sectors/track, 1044 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000de9ef

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1          26      204800   fd  Linux raid autodetect
Partition 1 does not end on cylinder boundary.
/dev/sda2              26        1045     8182784   fd  Linux raid autodetect

Disk /dev/sdb: 8589 MB, 8589934592 bytes
255 heads, 63 sectors/track, 1044 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00059799

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1   *           1          26      204800   fd  Linux raid autodetect
Partition 1 does not end on cylinder boundary.
/dev/sdb2              26        1045     8182784   fd  Linux raid autodetect

Disk /dev/md1: 8378 MB, 8378114048 bytes
2 heads, 4 sectors/track, 2045438 cylinders
Units = cylinders of 8 * 512 = 4096 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000


Disk /dev/mapper/vg_centoszrh-LogVol00: 1073 MB, 1073741824 bytes
255 heads, 63 sectors/track, 130 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000


Disk /dev/mapper/vg_centoszrh-LogVol02: 6765 MB, 6765412352 bytes
255 heads, 63 sectors/track, 822 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000


Disk /dev/mapper/vg_centoszrh-LogVol01: 536 MB, 536870912 bytes
255 heads, 63 sectors/track, 65 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000

Here is the output of df -hT

[root@localhost ~]# df -hT
Filesystem    Type    Size  Used Avail Use% Mounted on
/dev/mapper/vg_centoszrh-LogVol00
              ext3   1008M  744M  214M  78% /
tmpfs        tmpfs    504M     0  504M   0% /dev/shm
/dev/mapper/vg_centoszrh-LogVol02
              ext3    6.3G  143M  5.8G   3% /home

Tried to install Grub

[root@localhost ~]# grub-install /dev/sda
The file /boot/grub/stage1 not read correctly.