Grub Rescue error : Core.img not found- Help installing Ubuntu on External Hard Drive

[Sibetron]

Hello all,
I am a newbie to Ubuntu and wanted some help on getting the installation done on an external hard drive.

I have a Live USB version (11.04 Ubuntu) from where I am performing the installation.

I followed the steps mentioned in the following link
http://www.linuxbsdos.com/2011/05/23/install-ubuntu-11-04-on-external-hard-disk/

Installation went fine .
However, when I try to boot from external hard drive, I see a screen which says Grub Rescue> .

I searched online and found it had to do with the MBR not being setup correctly.

Just some info on my PC and external hard drive .

My internal Hard drive is drive : sda

SDB is my pen drive, where the Live USB is present.

My external hard drive is sdc .

On my external hard drive, initially the entire hard disk was formatted to NTFS and I used to use it for storage.
I created a free space of 25Gb on external hard drive for Ubuntu installation from WIn 7 using shrink volume feature.

SO due to this my hard drive had SDC1/SDC2 which were prior partitions , and after free space allocation, i further split them into Sdc3 - boot , sdc4 - Home , Sdc5 - swap area etc ....

I followed the steps mentioned in the following link
http://www.linuxbsdos.com/2011/05/23/install-ubuntu-11-04-on-external-hard-disk/

Under the “Device for boot loader installation” section, I selected the entry that matches the external disk that I just partitioned (SDC - External HD). I did NOT select SDC3 where the boot area of the Ubuntu installation is present .

I am not sure if that is the error.

On reading some posts i followed this one :
http://ubuntuforums.org/showthread.php?t=1528371

And captured the bootinfo . I see some error with regards to core.img not being found ? highlighted below. I am not sure if thats the problem though.

Can someone please help with this ?
Thanks for your help .

Below is the results.txt


Boot Info Script 0.60 from 17 May 2011


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

=> Windows is installed in the MBR of /dev/sda.
=> Syslinux MBR (4.04 and higher) is installed in the MBR of /dev/sdb.
=> Grub2 (v1.99) is installed in the MBR of /dev/sdc and looks at sector 1 of
the same hard drive for core.img. core.img is at this location and looks
for (,msdos3)/grub on this drive.

sda1: __________________________________________________ ________________________

File system: ntfs
Boot sector type: Windows Vista/7
Boot sector info: No errors found in the Boot Parameter Block.
Operating System: Windows 7
Boot files: /bootmgr /Boot/BCD /Windows/System32/winload.exe

sdb1: __________________________________________________ ________________________

File system: vfat
Boot sector type: SYSLINUX 4.04 2011-04-18
Boot sector info: Syslinux looks at sector 15274 of /dev/sdb1 for its
second stage. SYSLINUX is installed in the directory.
The integrity check of the ADV area failed. No errors
found in the Boot Parameter Block.
Operating System:
Boot files: /syslinux/syslinux.cfg /ldlinux.sys

sdc1: __________________________________________________ ________________________

File system: ntfs
Boot sector type: Windows XP
Boot sector info: No errors found in the Boot Parameter Block.
Operating System:
Boot files:

sdc2: __________________________________________________ ________________________

File system: ntfs
Boot sector type: Windows Vista/7
Boot sector info: No errors found in the Boot Parameter Block.
Operating System:
Boot files:

sdc3: __________________________________________________ ________________________

File system: ext2
Boot sector type: Grub2 (v1.99)
Boot sector info: Grub2 (v1.99) is installed in the boot sector of sdc3
and looks at sector 942295178 of the same hard drive
for core.img, but core.img can not be found at this
location.
Operating System:
Boot files: /grub/grub.cfg /grub/core.img

sdc4: __________________________________________________ ________________________

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

sdc5: __________________________________________________ ________________________

File system:
Boot sector type: -
Boot sector info:
Mounting failed: mount: unknown filesystem type ''

sdc6: __________________________________________________ ________________________

File system: ext4
Boot sector type: -
Boot sector info:
Operating System:
Boot files:

sdc7: __________________________________________________ ________________________

File system: ext4
Boot sector type: -
Boot sector info:
Operating System: Ubuntu 11.04
Boot files: /etc/fstab

sdc8: __________________________________________________ ________________________

File system:
Boot sector type: -
Boot sector info:
Mounting failed: mount: unknown filesystem type ''
mount: unknown filesystem type ''

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

Drive: sda __________________________________________________ ___________________

Disk /dev/sda: 160.0 GB, 160041885696 bytes
255 heads, 63 sectors/track, 19457 cylinders, total 312581808 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes

Partition Boot Start Sector End Sector # of Sectors Id System

/dev/sda1 * 2,048 312,578,047 312,576,000 7 NTFS / exFAT / HPFS


Drive: sdb __________________________________________________ ___________________

Disk /dev/sdb: 2004 MB, 2004877312 bytes
129 heads, 32 sectors/track, 948 cylinders, total 3915776 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes

Partition Boot Start Sector End Sector # of Sectors Id System

/dev/sdb1 * 32 3,915,775 3,915,744 c W95 FAT32 (LBA)


Drive: sdc __________________________________________________ ___________________

Disk /dev/sdc: 500.1 GB, 500107862016 bytes
255 heads, 63 sectors/track, 60801 cylinders, total 976773168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes

Partition Boot Start Sector End Sector # of Sectors Id System

/dev/sdc1 2,048 935,813,167 935,811,120 7 NTFS / exFAT / HPFS
/dev/sdc2 * 935,815,168 942,209,023 6,393,856 7 NTFS / exFAT / HPFS
/dev/sdc3 942,209,024 942,712,831 503,808 83 Linux
/dev/sdc4 942,714,878 976,771,071 34,056,194 5 Extended
/dev/sdc5 942,714,880 946,618,367 3,903,488 82 Linux swap / Solaris
/dev/sdc6 966,152,192 976,771,071 10,618,880 83 Linux
/dev/sdc7 946,620,416 962,097,151 15,476,736 83 Linux
/dev/sdc8 962,099,200 966,148,095 4,048,896 83 Linux


"blkid" output: __________________________________________________ ______________

Device UUID TYPE LABEL

/dev/loop0 squashfs
/dev/sda1 B23C58853C58468F ntfs SHISH
/dev/sdb1 130D-3153 vfat PENDRIVE
/dev/sdc1 22FE8FF0FE8FBA95 ntfs Elements
/dev/sdc2 86DA7A0BDA79F7AF ntfs PENDRIVE
/dev/sdc3 fe976c88-9f06-4950-a4ff-9d0b107077f5 ext2
/dev/sdc6 8d426315-1eb7-4fe4-8554-47807c08a855 ext4
/dev/sdc7 86a7f3c7-a328-464f-99e7-b2753ab1b3be ext4

================================ Mount points: =================================

Device Mount_Point Type Options

/dev/loop0 /rofs squashfs (ro,noatime)
/dev/sdb1 /cdrom vfat (ro,noatime,fmask=0022,dmask=0022,codepage=cp437,i ocharset=iso8859-1,shortname=mixed,errors=remount-ro)
/dev/sdc1 /media/Elements fuseblk (rw,nosuid,nodev,allow_other,blksize=4096,default_ permissions)
/dev/sdc2 /media/PENDRIVE fuseblk (rw,nosuid,nodev,allow_other,blksize=4096,default_ permissions)
/dev/sdc3 /media/fe976c88-9f06-4950-a4ff-9d0b107077f5 ext2 (rw,nosuid,nodev,uhelper=udisks)
/dev/sdc6 /media/8d426315-1eb7-4fe4-8554-47807c08a855 ext4 (rw,nosuid,nodev,uhelper=udisks)
/dev/sdc7 /media/86a7f3c7-a328-464f-99e7-b2753ab1b3be ext4 (rw,nosuid,nodev,uhelper=udisks)


========================= sdb1/syslinux/syslinux.cfg: ==========================

--------------------------------------------------------------------------------
# D-I config version 2.0
include menu.cfg
default vesamenu.c32
prompt 0
timeout 50

# If you would like to use the new menu and be presented with the option to install or run from USB at startup, remove # from the following line. This line was commented out (by request of many) to allow the old menu to be presented and to enable booting straight into the Live Environment!
# ui gfxboot bootlogo
--------------------------------------------------------------------------------

================= sdb1: Location of files loaded by Syslinux: ==================

GiB - GB File Fragment(s)

?? = ?? ldlinux.sys 1
?? = ?? syslinux/gfxboot.c32 1
?? = ?? syslinux/syslinux.cfg 1
?? = ?? syslinux/vesamenu.c32 1

============== sdb1: Version of COM32(R) files used by Syslinux: ===============

syslinux/gfxboot.c32 : COM32R module (v4.xx)
syslinux/vesamenu.c32 : COM32R module (v4.xx)

============================= sdc3/grub/grub.cfg: ==============================

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

### BEGIN /etc/grub.d/00_header ###
if [ -s $prefix/grubenv ]; then
set have_grubenv=true
load_env
fi
set default="0"
if [ "${prev_saved_entry}" ]; then
set saved_entry="${prev_saved_entry}"
save_env saved_entry
set prev_saved_entry=
save_env prev_saved_entry
set boot_once=true
fi

function savedefault {
if [ -z "${boot_once}" ]; then
saved_entry="${chosen}"
save_env saved_entry
fi
}

function recordfail {
set recordfail=1
if [ -n "${have_grubenv}" ]; then if [ -z "${boot_once}" ]; then save_env recordfail; fi; fi
}

function load_video {
insmod vbe
insmod vga
insmod video_bochs
insmod video_cirrus
}

insmod part_msdos
insmod ext2
set root='(/dev/sdc,msdos7)'
search --no-floppy --fs-uuid --set=root 86a7f3c7-a328-464f-99e7-b2753ab1b3be
if loadfont /usr/share/grub/unicode.pf2 ; then
set gfxmode=auto
load_video
insmod gfxterm
fi
terminal_output gfxterm
insmod part_msdos
insmod ext2
set root='(/dev/sdc,msdos3)'
search --no-floppy --fs-uuid --set=root fe976c88-9f06-4950-a4ff-9d0b107077f5
set locale_dir=($root)/grub/locale
set lang=en_US
insmod gettext
if [ "${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/light-gray
if background_color 44,0,30; then
clear
fi
### END /etc/grub.d/05_debian_theme ###

### BEGIN /etc/grub.d/10_linux ###
if [ ${recordfail} != 1 ]; then
if [ -e ${prefix}/gfxblacklist.txt ]; then
if hwmatch ${prefix}/gfxblacklist.txt 3; then
if [ ${match} = 0 ]; then
set linux_gfx_mode=keep
else
set linux_gfx_mode=text
fi
else
set linux_gfx_mode=text
fi
else
set linux_gfx_mode=keep
fi
else
set linux_gfx_mode=text
fi
export linux_gfx_mode
if [ "$linux_gfx_mode" != "text" ]; then load_video; fi
menuentry 'Ubuntu, with Linux 2.6.38-8-generic' --class ubuntu --class gnu-linux --class gnu --class os {
recordfail
set gfxpayload=$linux_gfx_mode
insmod part_msdos
insmod ext2
set root='(/dev/sdc,msdos3)'
search --no-floppy --fs-uuid --set=root fe976c88-9f06-4950-a4ff-9d0b107077f5
linux /vmlinuz-2.6.38-8-generic root=UUID=86a7f3c7-a328-464f-99e7-b2753ab1b3be ro quiet splash vt.handoff=7
initrd /initrd.img-2.6.38-8-generic
}
menuentry 'Ubuntu, with Linux 2.6.38-8-generic (recovery mode)' --class ubuntu --class gnu-linux --class gnu --class os {
recordfail
set gfxpayload=$linux_gfx_mode
insmod part_msdos
insmod ext2
set root='(/dev/sdc,msdos3)'
search --no-floppy --fs-uuid --set=root fe976c88-9f06-4950-a4ff-9d0b107077f5
echo 'Loading Linux 2.6.38-8-generic ...'
linux /vmlinuz-2.6.38-8-generic root=UUID=86a7f3c7-a328-464f-99e7-b2753ab1b3be ro single
echo 'Loading initial ramdisk ...'
initrd /initrd.img-2.6.38-8-generic
}
### END /etc/grub.d/10_linux ###

### BEGIN /etc/grub.d/20_linux_xen ###
### END /etc/grub.d/20_linux_xen ###

### BEGIN /etc/grub.d/20_memtest86+ ###
menuentry "Memory test (memtest86+)" {
insmod part_msdos
insmod ext2
set root='(/dev/sdc,msdos3)'
search --no-floppy --fs-uuid --set=root fe976c88-9f06-4950-a4ff-9d0b107077f5
linux16 /memtest86+.bin
}
menuentry "Memory test (memtest86+, serial console 115200)" {
insmod part_msdos
insmod ext2
set root='(/dev/sdc,msdos3)'
search --no-floppy --fs-uuid --set=root fe976c88-9f06-4950-a4ff-9d0b107077f5
linux16 /memtest86+.bin console=ttyS0,115200n8
}
### END /etc/grub.d/20_memtest86+ ###

### BEGIN /etc/grub.d/30_os-prober ###
menuentry "Windows 7 (loader) (on /dev/sda1)" --class windows --class os {
insmod part_msdos
insmod ntfs
set root='(/dev/sda,msdos1)'
search --no-floppy --fs-uuid --set=root B23C58853C58468F
chainloader +1
}
### 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 ###

### BEGIN /etc/grub.d/41_custom ###
if [ -f $prefix/custom.cfg ]; then
source $prefix/custom.cfg;
fi
### END /etc/grub.d/41_custom ###
--------------------------------------------------------------------------------

=================== sdc3: Location of files loaded by Grub: ====================

GiB - GB File Fragment(s)

449.503020287 = 482.650192896 grub/core.img 2
449.502021790 = 482.649120768 grub/grub.cfg 1
449.325525284 = 482.459609088 initrd.img-2.6.38-8-generic 73
449.295414925 = 482.427278336 vmlinuz-2.6.38-8-generic 19

=============================== sdc7/etc/fstab: ================================

--------------------------------------------------------------------------------
# /etc/fstab: static file system information.
#
# Use 'blkid -o value -s 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 nodev,noexec,nosuid 0 0
# / was on /dev/sdc7 during installation
UUID=86a7f3c7-a328-464f-99e7-b2753ab1b3be / ext4 errors=remount-ro 0 1
# /boot was on /dev/sdc3 during installation
UUID=fe976c88-9f06-4950-a4ff-9d0b107077f5 /boot ext2 defaults 0 2
# /home was on /dev/sdc6 during installation
UUID=8d426315-1eb7-4fe4-8554-47807c08a855 /home ext4 defaults 0 2
# swap was on /dev/sdc5 during installation
#UUID=3c4716c3-c6c3-454d-8c12-43013f6b9502 none swap sw 0 0
/dev/mapper/cryptswap1 none swap sw 0 0
--------------------------------------------------------------------------------

=============================== StdErr Messages: ===============================

unlzma: Decoder error
/home/ubuntu/Desktop/boot_info_script.sh: line 1579: [: 2.73495e+09: integer expression expected

[drs305]

Your system isn't finding core.img, which is generated by the grub-install command.

Boot a LiveCD and mount your Ubuntu partition, then the /boot partition. Then run the grub-install command again. Do not specify a partition in the third command:


sudo mount /dev/sdc7 /mnt
sudo mount /dev/sdc3 /mnt/boot
sudo grub-install --root-directory=/mnt /dev/sdc

When you reboot, make sure your BIOS is set to boot your SDC drive first.

Added:
I also see you are using a large drive and the grub files are located deep into the drive. If the above doesn't work, at the grub prompt. Use the "ls" command to determine which partition is your /boot partition. If it isn't (hd3,3), change the following command.

Corrected:

ls (hd2,3)/boot/grub
Does Grub find a lot of *.mod files?

[Sibetron]

Hey,

I tried the first 3 commands .
Basically I pasted from your post :
sudo mount /dev/sdc7 /mnt sudo mount /dev/sdc3 /mnt/boot sudo grub-install --root-directory=/mnt /dev/sdc
After that on rebooting I got an error
Grub Error : unknown filesystem.

On typing ls , it showed
(hd0) (hdo.msdos3) (hd0,msdos2) (hd0,msdos1) (hd1) (hd1,msdos1)

I tried
ls (hd3,3)/boot/grub


the error was : error : hd3 cannot get C/H/S values.

I am not sure regarding the *.mod files .

I still see the unknown file system error and the grub rescue screen.

[drs305]

Actually, I made an error and it should have been (hd2,3)/boot/grub. hd2 should be sdc, unless the computer reorders them.

However, Grub is seeing only two drives (hd0), (hd1). It is not seeing your third drive, which I assume is your Ubuntu drive since neither of the others lists more than 3 partitions.

Try this, but I don't think it's the correct drive:

ls (hd0,1)/boot/grub

[Sibetron]

Hey drs305,

i tried with (hd2,3)/boot/grub ,
however as you mentioned it looks as if hd2 is not seen at all . and this command failed with
error : hd2 cannot get C/H/S values

when I tried the other command with hd0,1 ,
it showed the error
unknown filesystem .

Any other clues as to how to fix it.

Thanks for your help.

[drs305]

I'm assuming you still have the same 3 devices connected that you did when you ran the boot info script. If so, Grub should find (hd0), (hd1) and (hd2).

Other than checking cables, etc I'm not good at troubleshooting this kind of problem. If you boot the LiveCD, can you see all the drives and partitions. You can run Gparted or use Disk Utility, or use the command line and run:

sudo blkid && sudo fdisk -l # lowercase L

If you are more comfortable in Windows, you should be able to boot into that OS if you change the BIOS to boot your Windows drive first.

I'll go through the RESULTS.txt again line by line but I don't know why Grub isn't seeing the drive.

Added: I see your fstab has a /dev/mapper listing. Did you use RAID at one time. (Note: I'm not a RAID user but know that remants of an old RAID setup can mess up Grub).

[Sibetron]

Yes, I have the same 3 devices connected.

I tried the ommand , and I am able to see the sdc listed .\
Here is the output

/dev/loop0: TYPE="squashfs"
/dev/sda1: LABEL="SHISH" UUID="B23C58853C58468F" TYPE="ntfs"
/dev/sdb1: LABEL="PENDRIVE" UUID="130D-3153" TYPE="vfat"
/dev/sdc1: LABEL="Elements" UUID="22FE8FF0FE8FBA95" TYPE="ntfs"
/dev/sdc2: LABEL="PENDRIVE" UUID="86DA7A0BDA79F7AF" TYPE="ntfs"
/dev/sdc3: UUID="fe976c88-9f06-4950-a4ff-9d0b107077f5" TYPE="ext2"
/dev/sdc6: UUID="8d426315-1eb7-4fe4-8554-47807c08a855" TYPE="ext4"
/dev/sdc7: UUID="86a7f3c7-a328-464f-99e7-b2753ab1b3be" TYPE="ext4"


Disk /dev/sda: 160.0 GB, 160041885696 bytes
255 heads, 63 sectors/track, 19457 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: 0x9b9a18af

Device Boot Start End Blocks Id System
/dev/sda1 * 1 19458 156288000 7 HPFS/NTFS

Disk /dev/sdb: 2004 MB, 2004877312 bytes
129 heads, 32 sectors/track, 948 cylinders
Units = cylinders of 4128 * 512 = 2113536 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xc3072e18

Device Boot Start End Blocks Id System
/dev/sdb1 * 1 949 1957872 c W95 FAT32 (LBA)
Partition 1 has different physical/logical endings:
phys=(956, 128, 32) logical=(948, 75, 32)

Disk /dev/sdc: 500.1 GB, 500107862016 bytes
255 heads, 63 sectors/track, 60801 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: 0x00157178

Device Boot Start End Blocks Id System
/dev/sdc1 1 58252 467905560 7 HPFS/NTFS
/dev/sdc2 * 58252 58650 3196928 7 HPFS/NTFS
/dev/sdc3 58650 58682 251904 83 Linux
/dev/sdc4 58682 60802 17028097 5 Extended
/dev/sdc5 58682 58925 1951744 82 Linux swap / Solaris
/dev/sdc6 60141 60802 5309440 83 Linux
/dev/sdc7 58925 59888 7738368 83 Linux
/dev/sdc8 59888 60140 2024448 83 Linux

Partition table entries are not in disk order

[drs305]

The only suggestion I can think of at the moment is to purge and reinstall Grub 2. I wrote a guide about it. First inspect the 3 and 7 partitions and make sure they have the boot files on 3 and the / files on 7. Then run the purge/reinstall chroot procedure, making sure to follow the additional instructions for users with a separate /boot partition.

http://ubuntuforums.org/showthread.php?t=1581099

[Sibetron]

I actually take my earlier response back.
While I am trying to boot from my external Hard drive, i remove the usb out (the Live USB) as it starts boot from that , instead of the external hard drive.

Probably thats the reason why we see only hd0 & hd1 .
I however tried all options at the grub menu ls (hd*,#)/boot/grub

* - 0 & 1
# 1,2,3,4

But still either i see filesystem unknown or i see partition not found as the error messages.

[drs305]

Are you getting all 7 or 8 partitions now? That was what I was concentrating on.

However, the normal 'ls' commands I gave you probably aren't correct since you have a separate boot.

Work your way up:

ls
ls (hdX,Y)/
ls (hdX,Y/grub

Even if you find the grub files, experiment to try to find the other Ubuntu files.

My main concern though is that it's not seeing all the partitions. Even if we find the /boot partition, if it doesn't see the others it won't matter.

[Sibetron]

The problem as you point out still remains.

My internal HD on Gparted shows up as sda1 & sda2 with sda 2 having unallocated space (10MB) .

The external HD has mainly 4 partitions ,
sdc1 - NTFS
sdc2 - NTFS
sdc3 - Boot - ext2
sdc4 - extended
Withing sdc4 is sdc 7 - ext4
and also within sdc4 is sdc 5 & sdc8 which are swap areas .

So by this i am assuming hd0 is this drive which comes up on grub.
The main problem seems to be why is it not seeing sdc7 ? which lies within sc4 in the hierarchy.

Also I am unsure why sdc 5/6/7 are listed as under sdc4 and not in the parent directory where sdc 1-4 are listed .

[drs305]

Boot into BIOS and see what the reported drive size is. If the drive is reported as 137GB or less, it's possible that you are running into a BIOS limitation. I've dealt with this issue many times before, but your indications are not the same. That could be because you have a separate boot partition but I don't think so.

If the BIOS reports a disk size of 137GB or less, I can provide some options. If it doesn't, I don't really have any more ideas other than deleting partitions 3 and higher, reformatting, and reinstalling Ubuntu.

I still don't fully understand the swap listing in your fstab, which includes 'dev/mapper/cryptswap'

[Hakunka-Matata]

The problem as you point out still remains.

My internal HD on Gparted shows up as sda1 & sda2 with sda 2 having unallocated space (10MB) .

The external HD has mainly 4 partitions ,
sdc1 - NTFS
sdc2 - NTFS
sdc3 - Boot - ext2
sdc4 - extended
Withing sdc4 is sdc 7 - ext4
and also within sdc4 is sdc 5 & sdc8 which are swap areas .

So by this i am assuming hd0 is this drive which comes up on grub.
The main problem seems to be why is it not seeing sdc7 ? which lies within sc4 in the hierarchy.

Also I am unsure why sdc 5/6/7 are listed as under sdc4 and not in the parent directory where sdc 1-4 are listed .

sdc5, 6, 7, & 8 are all Logical partitions, they live inside the Extended partition. sdc1,2,3,4 are all primary partitions. 1..4, are always primary partitions, and anything above 4 is a Logical.