Hi All,

I am new in linux. Stuck in a issue. Please help me.

I have already installed windoows 2008 R2 on the system. (/dev/sda1)
I have installed RHEL 5 in /dev/sda3 AND rhel 6 on /dev/sda6
I cannot install RHEL 5 and RHEL 6 on same machine. Following are the steps i did.

1. Installed RHEL 5 first and then RHEL 6.

While installing RHEL 6, I overwrite the MBR for Rhel 5.
I added entry for Rhel 5 while creating the grub during installation in Rhel 6. I mentioned the partition on which Rhel 5 was installed i.e. /dev/sda3
After successfully installing Rhel 6. When I tried to boot up in RHEL 5 from grub following error message was shown
"error 13 invalid unsupported executable format"

Following is the grub.conf file
[root@localhost ~]# cat /boot/grub/menu.lst
# 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 (hd0,5)
# kernel /boot/vmlinuz-version ro root=/dev/sda6
# initrd /boot/initrd-[generic-]version.img
#boot=/dev/sda
default=0
timeout=5
splashimage=(hd0,5)/boot/grub/splash.xpm.gz
hiddenmenu
title Red Hat Enterprise Linux (2.6.32-71.el6.x86_64)
root (hd0,5)
kernel /boot/vmlinuz-2.6.32-71.el6.x86_64 ro root=UUID=d7f6cd43-646a-4c0f-8f15-5ea72583e6b5 rd_NO_LUKS rd_NO_LVM rd_NO_MD rd_NO_DM LANG=en_US.UTF-8 SYSFONT=latarcyrheb-sun16 KEYBOARDTYPE=pc KEYTABLE=us crashkernel=128M rhgb quiet
initrd /boot/initramfs-2.6.32-71.el6.x86_64.img
title rhel 5
rootnoverify (hd0,2)
chainloader +1
title Other
rootnoverify (hd0,0)
chainloader +1

I mounted the rhel 5 /dev/sda3 partition in RHEL 6. Checked the files are present in /boot folder. They were present.
Then I copied the rhel 5 grub.conf's ENTRY into Rhel 6 grub.conf.
This was the updated grub.conf file

[root@localhost ~]# cat /boot/grub/menu.lst
# 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 (hd0,5)
# kernel /boot/vmlinuz-version ro root=/dev/sda6
# initrd /boot/initrd-[generic-]version.img
#boot=/dev/sda
default=0
timeout=5
splashimage=(hd0,5)/boot/grub/splash.xpm.gz
hiddenmenu
title Red Hat Enterprise Linux (2.6.32-71.el6.x86_64)
root (hd0,5)
kernel /boot/vmlinuz-2.6.32-71.el6.x86_64 ro root=UUID=d7f6cd43-646a-4c0f-8f15-5ea72583e6b5 rd_NO_LUKS rd_NO_LVM rd_NO_MD rd_NO_DM LANG=en_US.UTF-8 SYSFONT=latarcyrheb-sun16 KEYBOARDTYPE=pc KEYTABLE=us crashkernel=128M rhgb quiet
initrd /boot/initramfs-2.6.32-71.el6.x86_64.img
title rhel 5
root (hd0,2)
kernel /boot/vmlinuz-2.6.18-194.el5 ro root=LABEL=/1 rhgb quiet crashkernel=128M@16M
initrd /boot/initrd-2.6.18-194.el5.img
title Other
rootnoverify (hd0,0)
chainloader +1

STILL same error message was shown.

2. I installed Rhel 6 first and then RHEL 5.
While trying to boot Rhel 6 following error message was shown
"error 2 bad file or directory type"
I booted the system in RHEL 5 and again did all the things mentioned before. Still no output.

PLEASE can anybody help me out from this.

Thanks a lot

Ok, I'll start with a disclaimer that I use Debian rather than RHEL, and I've not tried multiple versions of linux on the same HD before.

However, I think what you need to do is install grub for RHEL 5 on that partition (/dev/sda3) and grub for RHEL 6 on that partition (/dev/sda6).

Last time I had a grub error I was able to run my install disk up to the point where it installed grub on the partition, then aborted the install process and everything else was left intact. (If you do this, make sure you don't let it change your partitions or format them again, unless you don't mind completely reinstalling the whole thing.)

--Bryan

Hey guys I finally got the solution.
Its pretty easy.
Install grub in MBR for RHEL 6.
Don't install any grub for RHEL 5. Skip the step.

Manually add the RHEL 5 entry in Rhel 6's /etc/grub.conf

And it works

Thanks,
beckham7