boot issue with tri-boot, grub2

[LMHmedchem]

I have added CentOS5.5 x86-64 to a linux box that already contains installations of Ubuntu 9 and SL 5.2. Grub2 was installed with Ubuntu and is on the MBR of the disk. I did not install grub with anaconda/Cent. Grub update in ubuntu finds the Cent install and addes it to the grub.conf, and Cent appears in the grub menu at boot. If I select Cent, I get the following error,

VFS: Cannot open root device "sda7" or unknown-block(0,0)
Please append a correct "root=" boot option

below is the output of [url=http://bootinfoscript.sourceforge.net/]boot_info_script[/url], which gives the relevant boot file data.

There are still grub conf files on the SL install, but grub is not installed there anymore. I don't know if the files are causing a problem or not.

Thanks for the help,

[b]LMHmedchem[/b]


[code] Boot Info Script 0.55 dated February 15th, 2010

============================= Boot Info Summary: ==============================

=> Grub 2 is installed in the MBR of /dev/sda and looks on the same drive in
partition #6 for /boot/grub.

sda1: _________________________________________________________________________

File system: swap
Boot sector type: -
Boot sector info:

sda2: _________________________________________________________________________

File system: Extended Partition
Boot sector type: -
Boot sector info:

sda5: _________________________________________________________________________

File system: swap
Boot sector type: -
Boot sector info:

sda6: _________________________________________________________________________

File system: ext3
Boot sector type: -
Boot sector info:
Operating System: Ubuntu 9.10
Boot files/dirs: /boot/grub/menu.lst /boot/grub/grub.cfg
/boot/grub/grub.conf /etc/fstab /boot/grub/core.img

sda7: _________________________________________________________________________

File system: ext3
Boot sector type: -
Boot sector info:
Operating System: CentOS release 5.5 (Final)
Kernel on an
Boot files/dirs: /etc/fstab

sda3: _________________________________________________________________________

File system: ext3
Boot sector type: -
Boot sector info:
Operating System: Scientific Linux SL release 5.2
(Boron) Kernel on an
Boot files/dirs: /boot/grub/menu.lst /boot/grub/grub.conf /etc/fstab

=========================== Drive/Partition Info: =============================

Drive: sda ___________________ _____________________________________________________

Disk /dev/sda: 320.1 GB, 320072933376 bytes
255 heads, 63 sectors/track, 38913 cylinders, total 625142448 sectors
Units = sectors of 1 * 512 = 512 bytes
Disk identifier: 0x0003cdeb

Partition Boot Start End Size Id System

/dev/sda1 63 3,903,794 3,903,732 82 Linux swap / Solaris
/dev/sda2 3,903,795 203,125,859 199,222,065 5 Extended
/dev/sda5 3,903,858 7,807,589 3,903,732 82 Linux swap / Solaris
/dev/sda6 7,807,653 105,466,724 97,659,072 83 Linux
/dev/sda7 105,466,788 166,899,284 61,432,497 83 Linux
/dev/sda3 * 203,125,860 254,325,014 51,199,155 83 Linux


blkid -c /dev/null: ____________________________________________________________

Device UUID TYPE LABEL

/dev/sda1 4972f29f-10ce-495f-95b2-b09358c28a08 swap
/dev/sda3 cd7875ae-8dfd-4e04-b32f-589f850118d2 ext3 SciLinux
/dev/sda5 2fd034d1-ebb2-4840-b188-67d19db97fd2 swap
/dev/sda6 d30ec437-c8f4-4ee7-93c6-ddf90369de41 ext3
/dev/sda7 90cecb53-19e2-4605-b35a-74a27570a1d3 ext3 /

============================ "mount | grep ^/dev output: ===========================

Device Mount_Point Type Options

/dev/sda6 / ext3 (rw,relatime,errors=remount-ro)


=========================== sda6/boot/grub/menu.lst: ===========================

# menu.lst - See: grub(8), info grub, update-grub(8)
# grub-install(8), grub-floppy(8),
# grub-md5-crypt, /usr/share/doc/grub
# and /usr/share/doc/grub-doc/.

## default num
# Set the default entry to the entry number NUM. Numbering starts from 0, and
# the entry number 0 is the default if the command is not used.
#
# You can specify 'saved' instead of a number. In this case, the default entry
# is the entry saved with the command 'savedefault'.
# WARNING: If you are using dmraid do not use 'savedefault' or your
# array will desync and will not let you boot your system.
default 0

## timeout sec
# Set a timeout, in SEC seconds, before automatically booting the default entry
# (normally the first entry defined).
timeout 3

## hiddenmenu
# Hides the menu by default (press ESC to see the menu)
hiddenmenu

# Pretty colours
#color cyan/blue white/blue

## password ['--md5'] passwd
# If used in the first section of a menu file, disable all interactive editing
# control (menu entry editor and command-line) and entries protected by the
# command 'lock'
# e.g. password topsecret
# password --md5 $1$gLhU0/$aW78kHK1QfV3P2b2znUoe/
# password topsecret

#
# examples
#
# title Windows 95/98/NT/2000
# root (hd0,0)
# makeactive
# chainloader +1
#
# title Linux
# root (hd0,1)
# kernel /vmlinuz root=/dev/hda2 ro
#

#
# Put static boot stanzas before and/or after AUTOMAGIC KERNEL LIST

### BEGIN AUTOMAGIC KERNELS LIST
## lines between the AUTOMAGIC KERNELS LIST markers will be modified
## by the debian update-grub script except for the default options below

## DO NOT UNCOMMENT THEM, Just edit them to your needs

## ## Start Default Options ##
## default kernel options
## default kernel options for automagic boot options
## If you want special options for specific kernels use kopt_x_y_z
## where x.y.z is kernel version. Minor versions can be omitted.
## e.g. kopt=root=/dev/hda1 ro
## kopt_2_6_8=root=/dev/hdc1 ro
## kopt_2_6_8_2_686=root=/dev/hdc2 ro
# kopt=root=UUID=d30ec437-c8f4-4ee7-93c6-ddf90369de41 ro

## default grub root device
## e.g. groot=(hd0,0)
# groot=d30ec437-c8f4-4ee7-93c6-ddf90369de41

## should update-grub create alternative automagic boot options
## e.g. alternative=true
## alternative=false
# alternative=true

## should update-grub lock alternative automagic boot options
## e.g. lockalternative=true
## lockalternative=false
# lockalternative=false

## additional options to use with the default boot option, but not with the
## alternatives
## e.g. defoptions=vga=791 resume=/dev/hda5
# defoptions=quiet splash

## should update-grub lock old automagic boot options
## e.g. lockold=false
## lockold=true
# lockold=false

## Xen hypervisor options to use with the default Xen boot option
# xenhopt=

## Xen Linux kernel options to use with the default Xen boot option
# xenkopt=console=tty0

## altoption boot targets option
## multiple altoptions lines are allowed
## e.g. altoptions=(extra menu suffix) extra boot options
## altoptions=(recovery) single
# altoptions=(recovery mode) single

## controls how many kernels should be put into the menu.lst
## only counts the first occurence of a kernel, not the
## alternative kernel options
## e.g. howmany=all
## howmany=7
# howmany=all

## should update-grub create memtest86 boot option
## e.g. memtest86=true
## memtest86=false
# memtest86=true

## should update-grub adjust the value of the default booted system
## can be true or false
# updatedefaultentry=false

## should update-grub add savedefault to the default options
## can be true or false
# savedefault=false

## ## End Default Options ##

title Ubuntu 9.10, kernel 2.6.31-23-generic
uuid d30ec437-c8f4-4ee7-93c6-ddf90369de41
kernel /boot/vmlinuz-2.6.31-23-generic root=UUID=d30ec437-c8f4-4ee7-93c6-ddf90369de41 ro quiet splash
initrd /boot/initrd.img-2.6.31-23-generic
quiet

title Ubuntu 9.10, kernel 2.6.31-23-generic (recovery mode)
uuid d30ec437-c8f4-4ee7-93c6-ddf90369de41
kernel /boot/vmlinuz-2.6.31-23-generic root=UUID=d30ec437-c8f4-4ee7-93c6-ddf90369de41 ro single
initrd /boot/initrd.img-2.6.31-23-generic

title Ubuntu 9.10, kernel 2.6.31-20-generic
uuid d30ec437-c8f4-4ee7-93c6-ddf90369de41
kernel /boot/vmlinuz-2.6.31-20-generic root=UUID=d30ec437-c8f4-4ee7-93c6-ddf90369de41 ro quiet splash
initrd /boot/initrd.img-2.6.31-20-generic
quiet

title Ubuntu 9.10, kernel 2.6.31-20-generic (recovery mode)
uuid d30ec437-c8f4-4ee7-93c6-ddf90369de41
kernel /boot/vmlinuz-2.6.31-20-generic root=UUID=d30ec437-c8f4-4ee7-93c6-ddf90369de41 ro single
initrd /boot/initrd.img-2.6.31-20-generic

title Ubuntu 9.10, kernel 2.6.31-19-generic
uuid d30ec437-c8f4-4ee7-93c6-ddf90369de41
kernel /boot/vmlinuz-2.6.31-19-generic root=UUID=d30ec437-c8f4-4ee7-93c6-ddf90369de41 ro quiet splash
initrd /boot/initrd.img-2.6.31-19-generic
quiet

title Ubuntu 9.10, kernel 2.6.31-19-generic (recovery mode)
uuid d30ec437-c8f4-4ee7-93c6-ddf90369de41
kernel /boot/vmlinuz-2.6.31-19-generic root=UUID=d30ec437-c8f4-4ee7-93c6-ddf90369de41 ro single
initrd /boot/initrd.img-2.6.31-19-generic

title Ubuntu 9.10, memtest86+
uuid d30ec437-c8f4-4ee7-93c6-ddf90369de41
kernel /boot/memtest86+.bin
quiet

### END DEBIAN AUTOMAGIC KERNELS LIST

=========================== sda6/boot/grub/grub.cfg: ===========================

#
# DO NOT EDIT THIS FILE
#
# It is automatically generated by /usr/sbin/grub-mkconfig using templates
# from /etc/grub.d and settings from /etc/default/grub
#

### BEGIN /etc/grub.d/00_header ###
if [ -s /boot/grub/grubenv ]; then
have_grubenv=true
load_env
fi
set default="0"
if [ ${prev_saved_entry} ]; then
saved_entry=${prev_saved_entry}
save_env saved_entry
prev_saved_entry=
save_env prev_saved_entry
fi
insmod ext2
set root=(hd0,6)
search --no-floppy --fs-uuid --set d30ec437-c8f4-4ee7-93c6-ddf90369de41
if loadfont /usr/share/grub/unicode.pf2 ; then
set gfxmode=640x480
insmod gfxterm
insmod vbe
if terminal_output gfxterm ; then true ; else
# For backward compatibility with versions of terminal.mod that don't
# understand terminal_output
terminal gfxterm
fi
fi
if [ ${recordfail} = 1 ]; then
set timeout=-1
else
set timeout=10
fi
### END /etc/grub.d/00_header ###

### BEGIN /etc/grub.d/05_debian_theme ###
set menu_color_normal=white/black
set menu_color_highlight=black/white
### END /etc/grub.d/05_debian_theme ###

### BEGIN /etc/grub.d/10_linux ###
menuentry "Ubuntu, Linux 2.6.31-23-generic" {
recordfail=1
if [ -n ${have_grubenv} ]; then save_env recordfail; fi
set quiet=1
insmod ext2
set root=(hd0,6)
search --no-floppy --fs-uuid --set d30ec437-c8f4-4ee7-93c6-ddf90369de41
linux /boot/vmlinuz-2.6.31-23-generic root=UUID=d30ec437-c8f4-4ee7-93c6-ddf90369de41 ro quiet splash
initrd /boot/initrd.img-2.6.31-23-generic
}
menuentry "Ubuntu, Linux 2.6.31-23-generic (recovery mode)" {
recordfail=1
if [ -n ${have_grubenv} ]; then save_env recordfail; fi
insmod ext2
set root=(hd0,6)
search --no-floppy --fs-uuid --set d30ec437-c8f4-4ee7-93c6-ddf90369de41
linux /boot/vmlinuz-2.6.31-23-generic root=UUID=d30ec437-c8f4-4ee7-93c6-ddf90369de41 ro single
initrd /boot/initrd.img-2.6.31-23-generic
}
menuentry "Ubuntu, Linux 2.6.31-20-generic" {
recordfail=1
if [ -n ${have_grubenv} ]; then save_env recordfail; fi
set quiet=1
insmod ext2
set root=(hd0,6)
search --no-floppy --fs-uuid --set d30ec437-c8f4-4ee7-93c6-ddf90369de41
linux /boot/vmlinuz-2.6.31-20-generic root=UUID=d30ec437-c8f4-4ee7-93c6-ddf90369de41 ro quiet splash
initrd /boot/initrd.img-2.6.31-20-generic
}
menuentry "Ubuntu, Linux 2.6.31-20-generic (recovery mode)" {
recordfail=1
if [ -n ${have_grubenv} ]; then save_env recordfail; fi
insmod ext2
set root=(hd0,6)
search --no-floppy --fs-uuid --set d30ec437-c8f4-4ee7-93c6-ddf90369de41
linux /boot/vmlinuz-2.6.31-20-generic root=UUID=d30ec437-c8f4-4ee7-93c6-ddf90369de41 ro single
initrd /boot/initrd.img-2.6.31-20-generic
}
menuentry "Ubuntu, Linux 2.6.31-19-generic" {
recordfail=1
if [ -n ${have_grubenv} ]; then save_env recordfail; fi
set quiet=1
insmod ext2
set root=(hd0,6)
search --no-floppy --fs-uuid --set d30ec437-c8f4-4ee7-93c6-ddf90369de41
linux /boot/vmlinuz-2.6.31-19-generic root=UUID=d30ec437-c8f4-4ee7-93c6-ddf90369de41 ro quiet splash
initrd /boot/initrd.img-2.6.31-19-generic
}
menuentry "Ubuntu, Linux 2.6.31-19-generic (recovery mode)" {
recordfail=1
if [ -n ${have_grubenv} ]; then save_env recordfail; fi
insmod ext2
set root=(hd0,6)
search --no-floppy --fs-uuid --set d30ec437-c8f4-4ee7-93c6-ddf90369de41
linux /boot/vmlinuz-2.6.31-19-generic root=UUID=d30ec437-c8f4-4ee7-93c6-ddf90369de41 ro single
initrd /boot/initrd.img-2.6.31-19-generic
}
### END /etc/grub.d/10_linux ###

### BEGIN /etc/grub.d/20_memtest86+ ###
menuentry "Memory test (memtest86+)" {
linux16 /boot/memtest86+.bin
}
menuentry "Memory test (memtest86+, serial console 115200)" {
linux16 /boot/memtest86+.bin console=ttyS0,115200n8
}
### END /etc/grub.d/20_memtest86+ ###

### BEGIN /etc/grub.d/30_os-prober ###
menuentry "Scientific Linux SL (2.6.18-194.17.1.el5) (on /dev/sda3)" {
insmod ext2
set root=(hd0,3)
search --no-floppy --fs-uuid --set cd7875ae-8dfd-4e04-b32f-589f850118d2
linux /boot/vmlinuz-2.6.18-194.17.1.el5 ro root=LABEL=SciLinux rhgb quiet crashkernel=128M@16M
initrd /boot/initrd-2.6.18-194.17.1.el5.img
}
menuentry "ScientificLinux (2.6.18-92.1.6.el5) (on /dev/sda3)" {
insmod ext2
set root=(hd0,3)
search --no-floppy --fs-uuid --set cd7875ae-8dfd-4e04-b32f-589f850118d2
linux /boot/vmlinuz-2.6.18-92.1.6.el5 ro root=LABEL=SciLinux rhgb quiet crashkernel=128M@16M
initrd /boot/initrd-2.6.18-92.1.6.el5.img
}
menuentry "CentOS release 5.5 (Final) (on /dev/sda7)" {
insmod ext2
set root=(hd0,7)
search --no-floppy --fs-uuid --set 90cecb53-19e2-4605-b35a-74a27570a1d3
linux /boot/vmlinuz-2.6.18-194.el5 root=/dev/sda7
}
### END /etc/grub.d/30_os-prober ###

### BEGIN /etc/grub.d/40_custom ###
# This file provides an easy way to add custom menu entries. Simply type the
# menu entries you want to add after this comment. Be careful not to change
# the 'exec tail' line above.
### END /etc/grub.d/40_custom ###

========================== sda6/boot/grub/grub.conf: ==========================

# menu.lst - See: grub(8), info grub, update-grub(8)
# grub-install(8), grub-floppy(8),
# grub-md5-crypt, /usr/share/doc/grub
# and /usr/share/doc/grub-doc/.

## default num
# Set the default entry to the entry number NUM. Numbering starts from 0, and
# the entry number 0 is the default if the command is not used.
#
# You can specify 'saved' instead of a number. In this case, the default entry
# is the entry saved with the command 'savedefault'.
# WARNING: If you are using dmraid do not use 'savedefault' or your
# array will desync and will not let you boot your system.
default 0

## timeout sec
# Set a timeout, in SEC seconds, before automatically booting the default entry
# (normally the first entry defined).
timeout 10

## hiddenmenu
# Hides the menu by default (press ESC to see the menu)
# hiddenmenu

# Pretty colours
#color cyan/blue white/blue

## password ['--md5'] passwd
# If used in the first section of a menu file, disable all interactive editing
# control (menu entry editor and command-line) and entries protected by the
# command 'lock'
# e.g. password topsecret
# password --md5 $1$gLhU0/$aW78kHK1QfV3P2b2znUoe/
# password topsecret

#
# examples
#
# title Windows 95/98/NT/2000
# root (hd0,0)
# makeactive
# chainloader +1
#
# title Linux
# root (hd0,1)
# kernel /vmlinuz root=/dev/hda2 ro
#

#
# Put static boot stanzas before and/or after AUTOMAGIC KERNEL LIST

### BEGIN AUTOMAGIC KERNELS LIST
## lines between the AUTOMAGIC KERNELS LIST markers will be modified
## by the debian update-grub script except for the default options below

## DO NOT UNCOMMENT THEM, Just edit them to your needs

## ## Start Default Options ##
## default kernel options
## default kernel options for automagic boot options
## If you want special options for specific kernels use kopt_x_y_z
## where x.y.z is kernel version. Minor versions can be omitted.
## e.g. kopt=root=/dev/hda1 ro
## kopt_2_6_8=root=/dev/hdc1 ro
## kopt_2_6_8_2_686=root=/dev/hdc2 ro
# kopt=root=UUID=d30ec437-c8f4-4ee7-93c6-ddf90369de41 ro

## default grub root device
## e.g. groot=(hd0,0)
# groot=d30ec437-c8f4-4ee7-93c6-ddf90369de41

## should update-grub create alternative automagic boot options
## e.g. alternative=true
## alternative=false
# alternative=true

## should update-grub lock alternative automagic boot options
## e.g. lockalternative=true
## lockalternative=false
# lockalternative=false

## additional options to use with the default boot option, but not with the
## alternatives
## e.g. defoptions=vga=791 resume=/dev/hda5
# defoptions=quiet splash

## should update-grub lock old automagic boot options
## e.g. lockold=false
## lockold=true
# lockold=false

## Xen hypervisor options to use with the default Xen boot option
# xenhopt=

## Xen Linux kernel options to use with the default Xen boot option
# xenkopt=console=tty0

## altoption boot targets option
## multiple altoptions lines are allowed
## e.g. altoptions=(extra menu suffix) extra boot options
## altoptions=(recovery) single
# altoptions=(recovery mode) single

## controls how many kernels should be put into the menu.lst
## only counts the first occurence of a kernel, not the
## alternative kernel options
## e.g. howmany=all
## howmany=7
# howmany=all

## specify if running in Xen domU or have grub detect automatically
## update-grub will ignore non-xen kernels when running in domU and vice versa
## e.g. indomU=detect
## indomU=true
## indomU=false
# indomU=detect

## should update-grub create memtest86 boot option
## e.g. memtest86=true
## memtest86=false
# memtest86=true

## should update-grub adjust the value of the default booted system
## can be true or false
# updatedefaultentry=false

## should update-grub add savedefault to the default options
## can be true or false
# savedefault=false

## ## End Default Options ##

title Ubuntu 9.04, kernel 2.6.28-13-generic
uuid d30ec437-c8f4-4ee7-93c6-ddf90369de41
kernel /boot/vmlinuz-2.6.28-13-generic root=UUID=d30ec437-c8f4-4ee7-93c6-ddf90369de41 ro quiet splash
initrd /boot/initrd.img-2.6.28-13-generic
quiet

title Ubuntu 9.04, kernel 2.6.28-13-generic (recovery mode)
uuid d30ec437-c8f4-4ee7-93c6-ddf90369de41
kernel /boot/vmlinuz-2.6.28-13-generic root=UUID=d30ec437-c8f4-4ee7-93c6-ddf90369de41 ro single
initrd /boot/initrd.img-2.6.28-13-generic

title Ubuntu 9.04, kernel 2.6.28-11-generic
uuid d30ec437-c8f4-4ee7-93c6-ddf90369de41
kernel /boot/vmlinuz-2.6.28-11-generic root=UUID=d30ec437-c8f4-4ee7-93c6-ddf90369de41 ro quiet splash
initrd /boot/initrd.img-2.6.28-11-generic
quiet

title Ubuntu 9.04, kernel 2.6.28-11-generic (recovery mode)
uuid d30ec437-c8f4-4ee7-93c6-ddf90369de41
kernel /boot/vmlinuz-2.6.28-11-generic root=UUID=d30ec437-c8f4-4ee7-93c6-ddf90369de41 ro single
initrd /boot/initrd.img-2.6.28-11-generic

title Ubuntu 9.04, memtest86+
uuid d30ec437-c8f4-4ee7-93c6-ddf90369de41
kernel /boot/memtest86+.bin
quiet

### END DEBIAN AUTOMAGIC KERNELS LIST

=============================== sda6/etc/fstab: ===============================

# /etc/fstab: static file system information.
#
# Use 'vol_id --uuid' to print the universally unique identifier for a
# device; this may be used with UUID= as a more robust way to name devices
# that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point> <type> <options> <dump> <pass>
proc /proc proc defaults 0 0
# / was on /dev/sdb6 during installation
UUID=d30ec437-c8f4-4ee7-93c6-ddf90369de41 / ext3 relatime,errors=remount-ro 0 1
# swap was on /dev/sdb1 during installation
UUID=4972f29f-10ce-495f-95b2-b09358c28a08 none swap sw 0 0
# swap was on /dev/sdb5 during installation
UUID=2fd034d1-ebb2-4840-b188-67d19db97fd2 none swap sw 0 0
/dev/scd0 /media/cdrom0 udf,iso9660 user,noauto,exec,utf8 0 0
/dev/fd0 /media/floppy0 auto rw,user,noauto,exec,utf8 0 0
## added to mount usb as rw
sysfs /sys sysfs defaults 0 0
usbfs /proc/bus/usb usbfs defaults 0 0
none /dev/shm tmpfs defaults 0 0
none /dev/pts devpts defaults 0 0

/dev/sda1 /media/Data_Volume/ ext3 defaults 0 0

=================== sda6: Location of files loaded by Grub: ===================


49.9GB: boot/grub/core.img
50.0GB: boot/grub/grub.cfg
50.0GB: boot/grub/grub.conf
49.9GB: boot/grub/menu.lst
49.9GB: boot/initrd.img-2.6.31-19-generic
49.9GB: boot/initrd.img-2.6.31-20-generic
50.0GB: boot/initrd.img-2.6.31-23-generic
49.9GB: boot/vmlinuz-2.6.31-19-generic
49.9GB: boot/vmlinuz-2.6.31-20-generic
49.9GB: boot/vmlinuz-2.6.31-23-generic
50.0GB: initrd.img
49.9GB: initrd.img.old
49.9GB: vmlinuz
49.9GB: vmlinuz.old

=============================== sda7/etc/fstab: ===============================

LABEL=/ / ext3 defaults 1 1
tmpfs /dev/shm tmpfs defaults 0 0
devpts /dev/pts devpts gid=5,mode=620 0 0
sysfs /sys sysfs defaults 0 0
proc /proc proc defaults 0 0
/dev/sdb5 swap swap defaults 0 0
LABEL=SWAP-sdb4 swap swap defaults 0 0
/dev/sdb1 swap swap defaults 0 0

=================== sda7: Location of files loaded by Grub: ===================


56.1GB: boot/initrd-2.6.18-194.el5.img
56.0GB: boot/vmlinuz-2.6.18-194.el5

========================== sda3/boot/grub/grub.conf: ==========================

# 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 (hd1,2)
# kernel /boot/vmlinuz-version ro root=/dev/sdb3
# initrd /boot/initrd-version.img
#boot=/dev/sda
default=0
timeout=10
splashimage=(hd1,2)/boot/grub/splash.xpm.gz
hiddenmenu
title Scientific Linux SL (2.6.18-194.17.1.el5)
root (hd1,2)
kernel /boot/vmlinuz-2.6.18-194.17.1.el5 ro root=LABEL=SciLinux rhgb quiet crashkernel=128M@16M
initrd /boot/initrd-2.6.18-194.17.1.el5.img
title ScientificLinux (2.6.18-92.1.6.el5)
root (hd1,2)
kernel /boot/vmlinuz-2.6.18-92.1.6.el5 ro root=LABEL=SciLinux rhgb quiet crashkernel=128M@16M
initrd /boot/initrd-2.6.18-92.1.6.el5.img

#title Ubuntu 9.04, kernel 2.6.28-13-generic
#uuid d30ec437-c8f4-4ee7-93c6-ddf90369de41
#kernel /boot/vmlinuz-2.6.28-13-generic root=UUID=d30ec437-c8f4-4ee7-93c6-ddf90369de41 ro #quiet splash
#initrd /boot/initrd.img-2.6.28-13-generic
#quiet

=============================== sda3/etc/fstab: ===============================

LABEL=SciLinux / ext3 defaults 1 1
tmpfs /dev/shm tmpfs defaults 0 0
devpts /dev/pts devpts gid=5,mode=620 0 0
sysfs /sys sysfs defaults 0 0
proc /proc proc defaults 0 0
/dev/sdb1 swap swap defaults 0 0
/dev/sdb5 swap swap defaults 0 0

=================== sda3: Location of files loaded by Grub: ===================


118.1GB: boot/grub/grub.conf
118.1GB: boot/grub/menu.lst
118.1GB: boot/grub/stage2
118.2GB: boot/initrd-2.6.18-194.17.1.el5.img
118.1GB: boot/initrd-2.6.18-194.17.1.el5kdump.img
118.2GB: boot/initrd-2.6.18-92.1.6.el5.img
118.1GB: boot/initrd-2.6.18-92.1.6.el5kdump.img
118.1GB: boot/vmlinuz-2.6.18-194.17.1.el5
118.1GB: boot/vmlinuz-2.6.18-92.1.6.el5[/code][b][color=000099]LMHmedchem[/color][/b]

[pschaff]

Welcome to the CentOS fora. Reading [url=https://www.centos.org/modules/newbb/viewforum.php?forum=47]FAQ & Readme First[/url] is recommended for new users.

[quote]
LMHmedchem wrote:
I have added CentOS5.5 x86-64 to a linux box that already contains installations of Ubuntu 9 and SL 5.2. Grub2 was installed with Ubuntu and is on the MBR of the disk. I did not install grub with anaconda/Cent. [/quote]
Unable to dig much helpful out of the information overload you have provided that would enable CentOS to boot easily, but I think the last statement above is the key anyway. Go ahead and install GRUB, but rather than letting it overwrite your GRUB2 MBR write the CentOS boot record to the CentOS boot partition using the Advanced option in anaconda. Looks like you did not create a /boot partition (not the recommended approach but may be OK) so that is /dev/sda7, GRUB device (hd0,6). You will then have a working /boot/grub/grub.conf to work from. Some people like to copy from that to create entries in the "master" GRUB2 config, but my preferred approach is to chainload to the secondary GRUB.

A stanza (or two) like the following, added to the Ubuntu menu.lst will do the trick:[code]
title chainload CentOS GRUB
root (hd0,6)
chainloader +1
title chainload Scientific Linux GRUB
root (hd0,2)
chainloader +1[/code]

This approach has the major advantage that it is "transparent" to the Ubuntu GRUB as far CentOS (or SL - [i][b]severely[/b][/i] overdue) kernel updates. Each OS updates its own kernel without the others having to take it into account.