Not able to boot linux machine.....

rajini23 · 02-14-2012, 11:03 PM

hi,

I have installed redhat5 OS in my desktop and later in secondary harddisk i have installed ubuntu OS,
Now i am not able to see my Rehat OS,Ubuntu is booting up has defualt OS,

Please help me on this...

My "fdisk output" of ubuntu....hear yout can find sda= Redhat5 installed and sdb=ubuntu installed.....

Disk /dev/sdb: 20.4 GB, 20416757760 bytes
255 heads, 63 sectors/track, 2482 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: 0xa869a869

Device Boot Start End Blocks Id System
/dev/sdb1 1 122 975872 83 Linux
Partition 1 does not end on cylinder boundary.
/dev/sdb2 122 2483 18959361 5 Extended
/dev/sdb5 122 487 2928640 82 Linux swap / Solaris
/dev/sdb6 487 2483 16029696 83 Linux

Disk /dev/sda: 40.0 GB, 40016019456 bytes
255 heads, 63 sectors/track, 4865 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: 0x0006ac66

Device Boot Start End Blocks Id System
/dev/sda1 * 1 127 1020096 83 Linux
/dev/sda2 128 509 3068415 83 Linux
/dev/sda3 510 4865 34989570 8e Linux LVM
user@user-desktop:~$

eeekster · 02-14-2012, 11:47 PM

When you installed Ubuntu on the other drive it put its own boot loader on the boot drive. You'll need to update Ubuntu's to include the Red Hat installation as a choice in the boot menu. For Red Hat (and Fedora) systems the configuration would be in /etc/grub.conf.

rajini23 · 02-15-2012, 12:05 AM

Hi,

I am not able to find any menu.lst file in my Ubuntu machine...i user ububt10.04 OS

eeekster · 02-15-2012, 04:22 AM

Quote:

Originally Posted by rajini23

I am not able to find any menu.lst file in my Ubuntu machine

Why were you looking for one?

Adol · 02-15-2012, 06:14 AM

Just find your grub.conf and edit it.

to edit mine, in a terminal with super user, I use:

Code:

nano /boot/grub/grub.conf

nano is the editor I use and the location points to my grub.conf

Your grub may be in another location so you need to look for it.

My grub looks like this for my gentoo install:

Code:

default 0
timeout 10
splashimage=(hd0,0)/boot/grub/splash.xpm.gz

title Gentoo Linux
root (hd0,0)
kernel /boot/gentoo-kernel root=/dev/sda2

make an entry and point grub to your os.

EDDY1 · 02-19-2012, 11:58 AM

Quote:

sudo update-grub

should find the other OS

slarti_42 · 02-22-2012, 12:44 AM

Yes, EDDY1 is right. Do not go meddling around with the configuration files unless you know what you are doing and have a good reason to do so. Grub is very good at finding OS's on its own - whenever you install a new OS and grub needs to find it, simply run the "sudo update-grub" command and it will look for all installed operating systems and automatically add them.

EDDY1 · 02-22-2012, 03:27 AM

If update-grub doesn't work when you run it mount the boot partition for sda & run it again.