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Boot Repair

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  Boot Repair "Martin McCormick" <martin.m@suddenlink.net> - 2021-06-02 20:00 +0200
    Re: Boot Repair Weaver <weaver@riseup.net> - 2021-06-02 20:40 +0200
      Re: Boot Repair "Martin McCormick" <martin.m@suddenlink.net> - 2021-06-02 22:10 +0200
        Re: Boot Repair Weaver <weaver@riseup.net> - 2021-06-02 22:30 +0200
      Re: Boot Repair "Martin McCormick" <martin.m@suddenlink.net> - 2021-06-03 05:10 +0200
        Re: Boot Repair Weaver <weaver@riseup.net> - 2021-06-03 05:30 +0200
          Re: Boot Repair "Martin McCormick" <martin.m@suddenlink.net> - 2021-06-03 19:10 +0200
            Re: Boot Repair Dan Ritter <dsr@randomstring.org> - 2021-06-03 20:10 +0200
              Re: Boot Repair. Still Going Round and Round. "Martin McCormick" <martin.m@suddenlink.net> - 2021-06-04 19:50 +0200

#235807 — Boot Repair

Is there any free utility that can run in Linux which helps one
rebuild a corrupted boot configuration?

	I have a disk which is currently out of it's usual place
as the boot drive for a debian system.  The past two times that
Buster updated grub, the drive became unbootable after  the
update.  The drive, itself appears to be perfectly good and I
think the problem which makes the update kill the drive is
related to a dd copy I made some years ago of one drive to
another so most of what is there is normal.

	After the second killing of the drive, I started to
determine what is misguiding update-initramfs as grub-install
seems to produce a grub.cfg file that is looking for all the
right UUID's but when the system boots, grub now fails by trying
to find a UUID that must have belonged to a now deceased system
as it no longer appears in the fstab of either the newly-dead
system or another system which is alive and well and being used
to try to revive the injured drive.

	Everything needed to produce a valid boot is there if
only I can run something that will reconstitude the boot image so
that it looks for the right UUID's.

	I do remember seeing this message as the update ripped
through the new grub:

update-initramfs: Generating /boot/initrd.img-4.19.0-5-686-pae
W: initramfs-tools configuration sets RESUME=UUID=6f6f4373-45a3-4c16-97b4-f62613
fe6d3b
W: but no matching swap device is available.

	That UUID should start with a 3, not a 6 as the blkid for
/swap is what should be there.

	I am not totally sure where tthe UUID that starts with
6f6f comes from but that's also the UUID one sees when grub
crashes and burns on liftoff when trying to boot from that drive.

Martin

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#235808

On 03-06-2021 03:59, Martin McCormick wrote:
> Is there any free utility that can run in Linux which helps one
> rebuild a corrupted boot configuration?

https://www.supergrubdisk.org/

Cheers!

Harry.

-- 
‘The issues are too important to be left for the voters’. 
― Henry Kissinger

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#235814

Weaver <weaver@riseup.net> writes:
> On 03-06-2021 03:59, Martin McCormick wrote:
> > Is there any free utility that can run in Linux which helps one
> > rebuild a corrupted boot configuration?
> 
> https://www.supergrubdisk.org/

	Thank you very much as you did answer my question
perfectly but I did not stop to think about all the possibilities
of the form the solution might take.

	So, as a computer user who happens to be blind, is this
stand-alone application using a linux kernel containing the
speakup modules?

	On the Linux live CD's, one can get those to talk by
striking the S key as the system boots up and then one can hear
what is on the screen as one works.

	Do you know what kind of kernel it uses?

	Martin

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#235815

On 03-06-2021 05:59, Martin McCormick wrote:
> Weaver <weaver@riseup.net> writes:
>> On 03-06-2021 03:59, Martin McCormick wrote:
>> > Is there any free utility that can run in Linux which helps one
>> > rebuild a corrupted boot configuration?
>>
>> https://www.supergrubdisk.org/
> 
> 	Thank you very much as you did answer my question
> perfectly but I did not stop to think about all the possibilities
> of the form the solution might take.
> 
> 	So, as a computer user who happens to be blind, is this
> stand-alone application using a linux kernel containing the
> speakup modules?

Absolutely no idea.
I should suspect it does as the size of the image infers a full kernel,
but they would know.

https://www.supergrubdisk.org/chat/

Cheers!

Harry.

-- 
‘The issues are too important to be left for the voters’. 
― Henry Kissinger

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#235826

Weaver <weaver@riseup.net> writes:
> https://www.supergrubdisk.org/

	The site recommends downloading the hybrid version of
grub2disk so that is what I did because all the Linux boxes I
have are x86 hardware and have CD technology built in.

	This is quite an interesting creation.  The ISO image is
a wee bit over 16 MB in size and, as I suspected, the package
includes no screen reader modules whatsoever but I did mount the
CD after burning it and ran

find . -name "*" -print and there are serial modules sprinkled
throughout the distribution.  There are occasional references to
a serial console.

	In some of the documentation I have found on the site, I
haven't found one iota of text as to how to make this console
work but if computer users who are blind can access this serial
console, that is like finding gold in them thare hills.

	Tomorrow, I will look further for any hints as to how to
make the serial console appear but I actually did read the words
"serial console" on that site.

	When I listed all the files on the CD, I also ran across
the following:

./boot/grub/i386-efi/morse.mod
./boot/grub/i386-pc/morse.mod
./boot/grub/x86_64-efi/morse.mod

	If this has to do with outputting text in Morse Code, I
know Morse since we amateur radio operators once had to know it
to get our licenses and as long as it is sending at a reasonable
rate which, for me, stops at about 20 words per minute, is
perfectly useful to read the output.

	I didn't even see any references to Morse Code on the
site so it's another way to make this useful.

	The PC being used to run this CD does have a piezo buzzer
on the mother board so if there is a way to make it sing in
Morse, I may not need the serial console but it certainly would
be nice to know all there is about both of those fall-back
methods.

	Thanks to anybody who knows where real sentences are that
explain the serial console or the possible Morse code output.

Martin WB5AGZ

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#235827

On 03-06-2021 13:02, Martin McCormick wrote:
> Weaver <weaver@riseup.net> writes:
>> https://www.supergrubdisk.org/
> 
> 	The site recommends downloading the hybrid version of
> grub2disk so that is what I did because all the Linux boxes I
> have are x86 hardware and have CD technology built in.
> 
> 	This is quite an interesting creation.  The ISO image is
> a wee bit over 16 MB in size and, as I suspected, the package
> includes no screen reader modules whatsoever but I did mount the
> CD after burning it and ran
> 
> find . -name "*" -print and there are serial modules sprinkled
> throughout the distribution.  There are occasional references to
> a serial console.
> 
> 	In some of the documentation I have found on the site, I
> haven't found one iota of text as to how to make this console
> work but if computer users who are blind can access this serial
> console, that is like finding gold in them thare hills.
> 
> 	Tomorrow, I will look further for any hints as to how to
> make the serial console appear but I actually did read the words
> "serial console" on that site.
> 
> 	When I listed all the files on the CD, I also ran across
> the following:
> 
> ./boot/grub/i386-efi/morse.mod
> ./boot/grub/i386-pc/morse.mod
> ./boot/grub/x86_64-efi/morse.mod
> 
> 	If this has to do with outputting text in Morse Code, I
> know Morse since we amateur radio operators once had to know it
> to get our licenses and as long as it is sending at a reasonable
> rate which, for me, stops at about 20 words per minute, is
> perfectly useful to read the output.
> 
> 	I didn't even see any references to Morse Code on the
> site so it's another way to make this useful.
> 
> 	The PC being used to run this CD does have a piezo buzzer
> on the mother board so if there is a way to make it sing in
> Morse, I may not need the serial console but it certainly would
> be nice to know all there is about both of those fall-back
> methods.
> 
> 	Thanks to anybody who knows where real sentences are that
> explain the serial console or the possible Morse code output.

Well, let us know how it goes, because I've noted a few visually
disadvantaged users on the list, and they would find the reference
useful.
If you have any further troubles, get back and there will be other
options.
Cheers!

Harry.

-- 
‘The issues are too important to be left for the voters’. 
― Henry Kissinger

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#235844

Weaver <weaver@riseup.net> writes:
> Well, let us know how it goes, because I've noted a few visually
> disadvantaged users on the list, and they would find the reference
> useful.

	I have found out that grub is very accessible if one has
defined a serial console and there is a working serial port on
the target system.  In this case, both conditions are true.

	The next thing one needs is a talking terminal which is
no problem if one has another computer equipped with a serial
terminal program like microcom or what I consider the gold
standard, kermit which apparently has too many dependencies to be
part of the Debian distributions any more.  Kermit has a decent
scripting language so one can save the commands that work, even
the commands that involve entering a huge string in which one
typo means completely starting over again.

	This means you can completely repeat all the things that
work each time and feed it all in again in a fraction of a
second.  Talk about working smarter as opposed to harder.

	While I call kermit the gold standard, the gold standard
for scripting is expect so one can call unix applications from
the login shell to any valid command, read the output and
generate commands as if one was there.  You can even simulate
human typing rhythms to defeat attempts to detect robots.  I'd
love to see a good CAPTCHA solver with OCR that was so good that
CAPTCHA designers would go out and find honest work but I digress.

	This is actually a systemic problem these days when
dealing with sick machines.  Nobody is selling new desktops
with RS-232 native serial ports and that is fine as long as
there is an alternative way such as a bluetooth interface or ssh
network connection.  The dream solution would be a local network
login covering all the lights-out conditions such as BIOS
configuration and failure to boot as in this situation where grub
is confused.

	Before I retired, some of our newest servers used
management interfaces and ipmitool where one could turn power on
and off, do BIOS setups and other configuration remotely.  It was
so cool to be able to do those things on a system in another town
without leaving the chair or grabbing a go bag and blowing a
whole day just to flip a couple of switches.  Of course,  
if it was that simple, we usually could call someone we trusted
at one of our remote campuses and ask them to flip the switches
but I'm sure you see the advantage of remote management.

	For folks who are blind, you treat all those things as if
they were halfway round the Earth instead of sitting less than 1
meter apart.  They are all headless even if I can extend my arms
and touch both machines.

	I think the grubdisk2 GUI app is basically a lost cause
but that's the rule when dealing with accessibility.  When
it's done wrong, you chase down endless rabbit holes all day and
muse as to how there must be some way to turn the sausage machine
backwards and have live farm animals running away from the
other end.

	There was an American country and Western song back in
the early seventies which had a line at the end of each verse
that went,

"Work your fingers to the bone
What do ya' get?
Bony fingers."

	I think the best course right now is to take my bony
fingers and workup a kermit script to interact with grub and get
it to produce one boot and then use the running system and grub
to fix itself.  So far, nothing else is less work.

	I do appreciate your telling me about grubdisk2 because
sometimes, these things turn out to be life savers and you have
to try the rabbit holes to know for sure.

Martin

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#235846

Martin McCormick wrote: 
> 	This is actually a systemic problem these days when
> dealing with sick machines.  Nobody is selling new desktops
> with RS-232 native serial ports and that is fine as long as
> there is an alternative way such as a bluetooth interface or ssh
> network connection.  The dream solution would be a local network
> login covering all the lights-out conditions such as BIOS
> configuration and failure to boot as in this situation where grub
> is confused.

I find serial ports frequently on:

NUC-style machines (not always, but often)
servers (always)
Supermicro motherboards

> 	For folks who are blind, you treat all those things as if
> they were halfway round the Earth instead of sitting less than 1
> meter apart.  They are all headless even if I can extend my arms
> and touch both machines.

You might consider getting someone to build you machines based
off of used server motherboards -- that way you will always have
full access to a text console covering BIOS function, booting,
and so forth.

Anything claiming to support IPMI (generic), iDRAC (Dell) or iLO (HP) 
should work nicely for this. Everyone complains that servers are
loud, but it's entirely an artifact of being in a short case
with high-speed fans. Build a desktop-sized system with a server
motherboard and it can be as quiet (or better!) than the next PC
over.

-dsr-

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#235888 — Re: Boot Repair. Still Going Round and Round.

I placed the ailing drive back on a good Linux system and mounted
it as /dev/sdd1 /mnt
and ran the following commands on it:

#!/bin/sh
#mount the drive being repaired.  Uncomment lines as needed.
  sudo mount /dev/sdd1 /mnt
cd /mnt/boot
#installing to the mounted disk
  sudo grub-install \
--boot-directory=/mnt/boot/ /dev/sda

Installing for i386-pc platform.
Installation finished. No error reported.
root@wb5agz:/#

But wait.  There's more.

root@wb5agz:/# update-grub --boot-directory=/dev/sda
Unrecognized option `--boot-directory=/dev/sda'

Not good.


Continuing on to update initramfs.

#Isolate the disk.


     sudo mount --bind /dev /mnt/dev
     sudo mount --bind /dev/pts /mnt/dev/pts
     sudo mount --bind /proc /mnt/proc
     sudo mount --bind /sys /mnt/sys

That all worked.

     sudo chroot /mnt
root@wb5agz:/# 
update-initramfs -c -k 4.19.0-5-686-pae

That appears to work.


root@wb5agz:/# update-grub
Generating grub configuration file ...
Found linux image: /boot/vmlinuz-4.19.0-5-686-pae
Found initrd image: /boot/initrd.img-4.19.0-5-686-pae
Found linux image: /boot/vmlinuz-4.9.0-9-686-pae
Found initrd image: /boot/initrd.img-4.9.0-9-686-pae

Now this ruins everything.

Found Debian GNU/Linux 10 (buster) on /dev/sdc1
done

This was a chroot environment but it appears that /dev/sdc1 was
recognized as the boot source for this external drive.  /dev is
part of the system.


	The external drive normally lives in another system and
is the only boot source which is why it should be /dev/sda1.

	Is there any way to run update-grub from grub itself?

	The system this external drive is meant for normally only
has 1 boot drive which is the one that is currently confusing
grub.  If I could run install-grub and update-grub from the dead
system, there would not be any other bootable drives and the only
game in town would be /dev/sda for the boot record and
/dev/sda1-5 for the boot drive.

	Understanding what is supposed to happen isn't
particularly difficult but getting grub to think simple and easy
	Putting the drive on another system and hoping for no
contamination seems to be a lot easier said than done.

Martin

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