Interrupted upgrade, reinstall, now Grub doesn't work

[Trevor Burton]

Hello everyone, I am in a mess.

Had a working WinXp/Karmic dual boot system
Tried to upgrade Karmic to Lucid and my daughter rebooted the system during the upgrade
I decided to do a fresh install of ubuntu, leaving Windows in place and it succeeded until the end when it said it could install the bootloader, so I proceeded without

Edit: I meant to say "it said it couldn't install the bootloader, so I proceeded without.

On booting, Grub drops to the command line.
I get grub>, not grub-rescue>
I did ls in grub and it showed the partitions I expected

/sda5 is /boot
/sda6 is /swap
/sda7 is /
/sda8 is /home

I tried to follow the grub2 command line manual by entering


set root=(hd0,7) (success)
linux /boot/vmlinuz-2.6.32-24-generic root=/dev/sda7 ro (failed - couldn't find file)

so I'm now a bit stuck.

Here are my bootinfo_script results
(by the way, sdb is just an e-SATA hard disc with nothing installed on it, I don't know why bootinfo thinks Windows is there. Windows is on /sda2 with some sort of backup/recovery partition on /sda1)



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 #7 for /boot/grub.
=> Windows is installed in the MBR of /dev/sdb

sda1: __________________________________________________ _______________________

File system: vfat
Boot sector type: Grub 2
Boot sector info: Grub 2 is installed in the boot sector of sda1 and
looks at sector 397263670 of the same hard drive for
core.img, but core.img can not be found at this
location. No errors found in the Boot Parameter Block.
Operating System: Windows 98
Boot files/dirs: /boot.ini /ntldr /NTDETECT.COM /IO.SYS /MSDOS.SYS
/COMMAND.COM

sda2: __________________________________________________ _______________________

File system: ntfs
Boot sector type: Windows XP
Boot sector info: No errors found in the Boot Parameter Block.
Operating System: Windows XP
Boot files/dirs: /BOOT.INI /NTLDR /NTDETECT.COM

sda3: __________________________________________________ _______________________

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

sda5: __________________________________________________ _______________________

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

sda6: __________________________________________________ _______________________

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

sda7: __________________________________________________ _______________________

File system: ext4
Boot sector type: -
Boot sector info:
Operating System: Ubuntu 10.04.1 LTS
Boot files/dirs: /etc/fstab /boot/grub/core.img

sda8: __________________________________________________ _______________________

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

sdb1: __________________________________________________ _______________________

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

=========================== 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
Sector size (logical/physical): 512 bytes / 512 bytes

Partition Boot Start End Size Id System

/dev/sda1 63 16,370,234 16,370,172 1b Hidden W95 FAT32
/dev/sda2 * 16,370,235 387,471,734 371,101,500 7 HPFS/NTFS
/dev/sda3 387,473,406 625,141,759 237,668,354 5 Extended
/dev/sda5 387,473,408 387,676,159 202,752 83 Linux
/dev/sda6 387,678,208 396,064,767 8,386,560 82 Linux swap / Solaris
/dev/sda7 396,066,816 458,979,327 62,912,512 83 Linux
/dev/sda8 458,981,376 625,141,759 166,160,384 83 Linux


Drive: sdb ___________________ __________________________________________________ ___

Disk /dev/sdb: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders, total 1953525168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes

Partition Boot Start End Size Id System

/dev/sdb1 63 1,953,520,064 1,953,520,002 7 HPFS/NTFS


blkid -c /dev/null: __________________________________________________ __________

Device UUID TYPE LABEL

/dev/loop0 squashfs
/dev/sda1 44D7-70B8 vfat BACKUP
/dev/sda2 4A38F4AD38F498E1 ntfs HDD
/dev/sda3: PTTYPE="dos"
/dev/sda5 3360563b-d9f2-49cd-b2d8-5e940dffd602 ext4
/dev/sda6 a802ec63-61fe-4196-99d6-93d3adc55f7a swap
/dev/sda7 49017298-36c8-4545-9ad4-cf33ce252549 ext4
/dev/sda8 15c85799-332f-47af-b367-c4cd40d12597 ext4
/dev/sda: PTTYPE="dos"
/dev/sdb1 6EDEDBBFDEDB7E31 ntfs Elrond
/dev/sdb: PTTYPE="dos"
error: /dev/sdc: No medium found
error: /dev/sdd: No medium found
error: /dev/sde: No medium found
error: /dev/sdf: No medium found

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

Device Mount_Point Type Options

aufs / aufs (rw)
/dev/sr0 /cdrom iso9660 (ro,noatime)
/dev/loop0 /rofs squashfs (ro,noatime)


================================ sda1/boot.ini: ================================

[boot loader]
timeout=0
default=C:\CMDCONS\BOOTSECT.DAT
[operating systems]
C:\CMDCONS\BOOTSECT.DAT="Windows PE Recovery Process W/O Data losing" /cmdcons
C:\BOOTSECT.DOS="MS-Dos OEMSETUP Recovery Process..."

================================ sda2/BOOT.INI: ================================

[boot loader]
timeout=3
default=multi(0)disk(0)rdisk(0)partition(2)\WINDOW S
[operating systems]
multi(0)disk(0)rdisk(0)partition(2)\WINDOWS="Windows XP Media Center Edition" /noexecute=optin /fastdetect
C:\CMDCONS\BOOTSECT.DAT="Microsoft Windows Recovery Console" /cmdcons

=================== sda5: Location of files loaded by Grub: ===================


198.4GB: initrd.img-2.6.32-24-generic
198.4GB: vmlinuz-2.6.32-24-generic

=============================== sda7/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
/dev/sda7 / ext4 errors=remount-ro 0 1
# /boot was on /dev/sda5 during installation
UUID=3360563b-d9f2-49cd-b2d8-5e940dffd602 /boot ext4 defaults 0 2
# /home was on /dev/sda8 during installation
UUID=15c85799-332f-47af-b367-c4cd40d12597 /home ext4 defaults 0 2
/dev/sda6 none swap sw 0 0

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


233.5GB: boot/grub/core.img
=======Devices which don't seem to have a corresponding hard drive==============

sdc sdd sde sdf


Any ideas?

Thanks

[ronparent]

The code you entered at the grub prompt was in error according to your results.txt. Your kernel is actually located in your /boot on sda5 (also known in grub 2 terms as (hd0,5)). I personally see no reason for a separate boot partition unless you have installed to a software raid or LVM partition. In any event no /boot/grub/grub.cfg was found. Without that file there is no grub menu. I would normally suggest reinstalling grub. In your case you could probably best reinstall 10.04 with only the separate /home (no formating of course) and the /. If you are sure that your /boot contains all the /boot system files you need to boot you could try a grub 2 reinstall. Use this reference (https://help.ubuntu.com/community/Grub2#Reinstalling GRUB 2) to tell you how. I believe your root designation (which you mount to /mnt) would be your /boot partition. Let us know if you have any problems. Good luck.

[drs305]

Edited:

You don't have a grub.cfg file. You can chroot into your Ubuntu installation and reinstall grub-pc. See the G2-Chroot link in my signature line.

The method of reinstalling Ubuntu via LiveCd as mentioned by ronparent will also work but make sure you don't format anything!

[drs305]

Added:
If your files are otherwise intact, I can probably give you the grub prompt commands to boot if you would prefer to do it that way.

Further Added:
Upon further review, I don't think you will be able to boot from the grub prompt. In addition to not having a grub.cfg file (which isn't needed for a boot from the prompt), the core.img file which should be in /boot/grub is located in your main partition. I don't know how it got there.

It's possible that moving core.img back to /boot/grub from a LiveCD would work, but possibly not. A more certain approach would be to purge/reinstall Grub via the 'chroot' method. Make sure you mount both sda7 (/) and sda5 (/boot) before you enter the chroot. It's explained in the guide. The guide doesn't cover it, but you should also mount your /home partition as well.

[ToFue]

... I personally see no reason for a separate boot partition unless you have installed to a software raid or LVM partition.

I do it to play with grub, modules & kernels from windows as ext2, using ext2.dll in windows (though others claim it read/writes ext3, it never did for me)

Trevor: I suppose you've gotten it worked out by now, but lemme say that I second drs305 and the others- LiveCD, then chroot then the grub installation method suggested by the other guys... after all, it's a complete new system install, minus grub. If you would have let the install happen, it would have went fine, configuring the chainloader for the windows boot entry automatically..

ronparent's link to the grub 2 guide is a great guide that helped me out before!

Also, I would venture that there's no grub.cfg file b/c grub hadn't completed a sucessful boot- that the file gets rewritten to whatever the last successful config was, and editing it would be pointless.. (just a guess)

also check out
$ info grub
And don't forget to check ownerships/permissions of your old /home once you're up with the new system ;)

[Trevor Burton]

Thanks everyone for the responses.

I chickened out of configuring/reinstalling grub and did a reinstall of Ubuntu but with just partitions for /swap, /home and /.

Then it booted up perfectly.

Not sure why the install didn't like a separate /boot partition, (I don't think I did anything else differently).

Unfortunately, Lucid is far less responsive on my gui than Karmic was - it takes around 3 seconds to show shortcut menus for example and dragging windows is virtually impossible (I drag and drop and wait for the window to follow some seconds later) - however, that is a different problem, so I'll make a new thread.

I think the message of all this is
1) don't let anyone near your computer during an upgrade
2) ? don't specify a separate /boot partition as the installer seems to have troubles (well, maybe, at least it did for me)

Thanks all, Trevor

[ToFue]

Lol Those are lessons I take to heart!

Out of curiosity of the lag issue, how big is your swap? If it's 8Gb like your earlier post suggests you've attempted, it may be too large. It's possible that the system is read/writing to swap for everything it can before shoving to RAM for the quick execution...

As a test to rule this out is in the code frame; bassically turn swap off, check things out, then if that's not it then turn swap back on and snoop elsewhere. If the lag Does improve then you'll probably have to rethink the size of your swap partition & shrink it

First see what partition swap is. For me, it was /dev/sda5, just replace with what fdisk tells you it is:




$ sudo fdisk -l



Then turn off the swap:




$ sudo swapoff /dev/sda5



Now check things out in gnome- see if the lag went away

To turn swap back on:




$ sudo swapon /dev/sda5




Ideally (for personal 'puter) you want no more than 2Gb of swap space before the benefit of swap becomes moot. I believe the rule of thumb is that you want twice the amount for Swap as you do for RAM except to not exceed 2Gb. So if you have 500Mb RAM, you'd set up 1Gb Swap; 1G RAM:2G.....

Without getting really into it, the Swap's function was to compensate for a lack of RAM. With today's computers allowing 4+ Gb of ram, the need for swap becomes less meaningful, but still important for the swap functionality provided by application being designed with swap in mind such as the hibernate power-down feature..

[Trevor Burton]

...

Out of curiosity of the lag issue, how big is your swap? If it's 8Gb like your earlier post suggests you've attempted, it may be too large.

....

Thanks for that ToFue, I think I did reduce the swap size when I reinstalled actually, but to 4Gb. However, the slowness was due to a bug in Lucid to do with kernel mode setting which I believe was introduced in Lucid - I've disabled kernel mode setting and now graphics are working at normal speed.

Here's the reference from
wiki.ubuntu.com (https://wiki.ubuntu.com/LucidLynx/ReleaseNotes#Working%20around%20bugs%20in%20the%20 new%20kernel%20video%20architecture)

Trevor