Re: Reconciling multiple GrUBs and development...

[Jordan Uggla]

First, I would like to mention that it is bad netiquette to send HTML
email to technical mailing lists like help-grub. Please stick to plain
text in the future.

On Fri, Sep 23, 2011 at 9:55 AM, Eli Riedlinger <address@hidden> wrote:
> To whomever may wish to comment on any issue mentioned herein...
>
> I operate an IBM ThinkPad...
> If I do not have a certain mostly full 90+GB USB drive plugged in I get the
> message:
>  "error: no such device ac9......-....-....-....-.......... ."
>   "grub rescue >"

This error means that your bios booted from a drive whose master boot
record and post-mbr gap held a grub installation's boot sector and
core.img, but this core.img was looking for /boot/grub on another
drive. A drive which was not accessible to the BIOS (and therefore to
grub) at the time you received this error. Most likely it wasn't
accessible because it simply wasn't plugged in or the partition that
once contained that /boot/grub/ has been deleted.

>
> I have no idea how to respond to this except to re-plug in the USB drive and
> manually reboot...
>
> If the 90+GB USB drive is plugged in boots to GNU Grub V 198+20100804-5
> ubuntu 3-1mint1
> This GrUB gives me the following main boot options:
>   Linux Mint 10,2.6.35-2-generic (/dev/sdb1)
>   Linux Mint ... recovery ... [which I do not know how to use...]
>   2 Memory check options and...
>   Microsoft Windows XQ Professional (/dev/sda1?)
> Linux Mint is installed on the 90+GB USB drive  and boots fine to the login
> screen
>
> Then upon login Linux Mint stalls, probably because of one or more bad or
> incompatible packages installed...
> Under Windows I have installed Wubi XUbuntu...
> So when I select the Windows option, I get next get what appears to be a
> Windows boot menu:
>
> "Please select the operating system to start
>   "Microsoft Windows XQ Professional
>   "Xubuntu
> "use...keys...to your choice"
> "Press ENTER to choose
>
> "For ... options for Windows, press F8"
>
> If I select the Windows option, it boots and runs just fine, except that
> hard drive is almost full and cannot read either Linux information except
> apparently the Linux Mint and XUbuntu grub files in main directories on c:\
>
> If I select Xubuntu, a SECOND GrUB shows up with the following sub-boot
> options:
>   Ubuntu Linux 2.6.38-11-generic
>   Ubuntu Linux 2.6.38-8-generic
>   Mirosoft Windows XP Professional (on dev/sda1) [which I have not selected]
>   Linux Mint 10, 2.6.35-22-generic (.dev/sdb1) (on dev/sdb1)...
> I generally just select Ubuntu...-11... and that is from where this email is
> being sent...
>
> I have not yet run Windows or Linux Mint from this third boot menu...
>
> XUbuntu boots up fine from that menu, though I have not yet tried Windows
> Linux Mint from the second GrUB menu...
>
> The main issue is that I'm afraid to try to install any other OS because I
> fear I will lose the ability to boot this computer...
>
> I thought that if Linux was installed on a USB drive, that OS could be
> booted from any computer, though that is not the current functioning...
>
> The Linux Mint directories are accessable from XUbuntu, though not my
> downloads in the login folder, which are probably using up most of the drive
> and I would like to recover if possible...
> I need to:
>   1) if possible recover the files from the Linux Mint home sub-directory
>   2) reconcile the three boot menus so I can go directly to any OS directly
> from one boot menu
>   3) regain access to the storage available on the 90+GB USB drive for
> further development goals
>   4) set up the main ThinkPad drive so it can boot without a USB drive
> plugged in
>   5) set up the USB drive so it can boot to one or more versions of Linux
> and/or Ubuntu when plugged in
>   6) install Ubuntu 10 server, or another version of Linux with server
> capabilities,
>         yet I know nothing about setting up or running a server
>   7) set up a version of Linux that can easily install a version of Pascal
> compiling to GNU...
>         (GNU Pascal is primarily only for Windows and Mac or Apple...)
>         (Free Pascal does not appear to compile to GNU...)
>   8) learn how much programming is possible just running GrUB
>   9) learn how much code it takes to make a GrUB and how to extend its
> functionality
>
> The concept of boot stages intrigues me, even though it currently only
> functions on my computer in a redundant fashion because of how Linux Mint
> limits the functionality of Windows, the fact that Windows basically cannot
> read Linux partitions on its own and the reality that wubi installed Xubuntu
> under Windows and was therefore limited in its installation options to the
> drives visible from Windows, even though after installation, Xubuntu could
> at least see the folders in the Linux Mint drive...
>
> It is probably true that most versions of Linux share a lot of code and
> different Linux OS's share dependencies...

To be honest you may have given enough information here for me to
determine enough about your situation to give you a complete answer,
but it would be much easier for me if you could run boot info script
as explained here: http://ubuntuforums.org/showthread.php?t=1291280
and reply with the contents of the RESULTS.txt that boot info script
produces (simply inline in the email rather than an attachment, and
still plain text, would be most convenient).

>
> I would like to install or program a version of Linux or Xen or other
> hypervisor that can do something like run different OS's in different
> workspaces, as if they all shared common GNU/CLR kernel code and just
> implemented different GUI desktop appearances on different workspace
> pages...  I once saw a program that could do that, though do not remember
> its name...
>
> If I knew enough about the hypervisor varierties, the various Linux versions
> with their many relevant packages available in the various package managers
> of the various Linux versions, also considering the possibility of sync
> functionality, something like that might already exist or possibly be built
> with existing software...
>
> GNU and various GrUBs interface with every hardware, though I don't yet
> comprehend exactly how much is set up under GrUB and how much is left to the
> OS to setup...
>
> I apologize if I have gone beyond the scope of this message board...

Indeed, that is beyond the scope of help-grub.

>
> I have issues I need to resolve and ideas I wish to develop and the two are
> related in my mind...
>
> Sincerely, Elijah...
>
> _______________________________________________
> Help-grub mailing list
> address@hidden
> https://lists.gnu.org/mailman/listinfo/help-grub
>
>

To give you a more concrete answer specific to your situation I'll
need to see the boot info script output mentioned above, but in
general for any *non-wubi* installations of Ubuntu I would recommend
you boot said installation, plugging in whatever drives necessary to
currently do so, then within that install run "sudo dpkg-reconfigure
grub-pc".

That command will prompt you for configuration options for the grub-pc
package. You are only interested in the "install devices" option, so
leave all other prompts at their default and continue. When you get to
the install devices question select the drive that contains the
partition you're currently booted from, and nothing else. Read that
last sentence carefully. For instance, if you have booted from an
Ubuntu installation on /dev/sdb5 you would want to select "sdb" as
your only install device (*not* sdb5). Select and unselect install
devices with space bar, continue on to the next prompt with Enter. And
once again, this does not apply to Wubi installations which are a bit
odd in how grub is dealt with.

-- 
Jordan Uggla (Jordan_U on irc.freenode.net)