[CentOS] Two CentOS installations failed dual boot

Thu Jun 14 09:12:10 UTC 2012
Amindeed <amindeed.techlists at gmail.com>

Hello everybody,

I installed Centos 6.2 on a computer with an older version of it in 
order to dual boot both of them. I managed to install the new OS on a 
physically seperated hard drive, and configured grub to make the newly 
installed OS the default one.  Now the older OS won't boot and this 
error message shows: *"error 13: invalid or unsupported executable format"*.
I attached to the email the output of *"fdisk -l"*  and a copy of the 
*"/etc/grub.conf"* configuration file.

I have no experience dealing with boot/grub issues, so any help on this 
will be much appreciated.

Regards.
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[root at mypc ~]# fdisk -l

Disk /dev/sda: 80.0 GB, 80000000000 bytes
255 heads, 63 sectors/track, 9726 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: 0x00000080

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1        9472    76077056   83  Linux
/dev/sda2            9472        9726     2045952   82  Linux swap / Solaris

Disk /dev/sdb: 80.0 GB, 80032038912 bytes
255 heads, 63 sectors/track, 9730 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: 0xdbdbdbdb

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1   *           1          13      104391   83  Linux
/dev/sdb2              14        9730    78051802+  8e  Linux LVM

Disk /dev/mapper/VolGroup00-LogVol01: 2080 MB, 2080374784 bytes
255 heads, 63 sectors/track, 252 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: 0x30307800

Disk /dev/mapper/VolGroup00-LogVol01 doesn't contain a valid partition table

Disk /dev/mapper/VolGroup00-LogVol00: 77.8 GB, 77812727808 bytes
255 heads, 63 sectors/track, 9460 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/VolGroup00-LogVol00 doesn't contain a valid partition table
[root at mypc ~]# 
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# 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 (hd1,0)
#          kernel /boot/vmlinuz-version ro root=/dev/sda1
#          initrd /boot/initrd-[generic-]version.img
#boot=/dev/sdb
default=0
timeout=5
splashimage=(hd1,0)/boot/grub/splash.xpm.gz
hiddenmenu
title CentOS (2.6.32-220.17.1.el6.i686)
	root (hd1,0)
	kernel /boot/vmlinuz-2.6.32-220.17.1.el6.i686 ro root=UUID=b5d4d678-1e3d-47ce-acf1-d061097b6885 rd_NO_LUKS  KEYBOARDTYPE=pc KEYTABLE=fr LANG=en_US.UTF-8 rd_NO_MD quiet SYSFONT=latarcyrheb-sun16 rhgb crashkernel=auto rd_LVM_LV=VolGroup00/LogVol01 rd_NO_DM
	initrd /boot/initramfs-2.6.32-220.17.1.el6.i686.img
title CentOS IPBX (2.6.32-220.el6.i686)
	root (hd1,0)
	kernel /boot/vmlinuz-2.6.32-220.el6.i686 ro root=UUID=b5d4d678-1e3d-47ce-acf1-d061097b6885 rd_NO_LUKS  KEYBOARDTYPE=pc KEYTABLE=fr LANG=en_US.UTF-8 rd_NO_MD quiet SYSFONT=latarcyrheb-sun16 rhgb crashkernel=auto rd_LVM_LV=VolGroup00/LogVol01 rd_NO_DM
	initrd /boot/initramfs-2.6.32-220.el6.i686.img
title VoisGate
	rootnoverify (hd0,0)
	chainloader +1