Re: unetbootin rendered system unbootable

[lejeczek]

On 23/01/18 22:35, sashab wrote:
> Hi L,
>
> please beware: all advice below are IMHO and AFAIK (and i'm a novice, too).
>
> First of all, the obvious: Is your laptop set to boot "UEFI" (after you
> may have tried to boot FreeDos via "legacy boot")?
>
> Have you checked the contents of your EFI-Partition /dev/sda1?
> Especially if there is EFI/fedora/grubx64.efi?
>
> Have you checked the contents of your /boot partition /dev/sda2?
> Especially if there are grub-modules inside /boot/grub/* and a valid
> config in /boot/grub/grub.cfg.
>
> For missing grub modules you may want to chroot in your installed os and
> do a grub-install there. Maybe also append "--target=x86_64-efi" to that
> command.
> For missing config you probably want a "grub-mkconfig -O
> /boot/grub/grub.cfg" within your chroot.
>
> According efivars:
> By pressing "F12" or something it should be possible to get a menu to
> choose a boot option before the firmware actually tries to boot.
> What are the entries presented there?
> (You may wish do add --bootloader-id=test to your grub-install call to
> be sure that you're choosing the right entry. However, after doing so
> later you'll have to cleanup the efi variable mess.)
> You may visit wiki.archlinux.org for more info on handling uefi stuff.
>
> Regards,
>      sashab
>
>
>
> On 23/01/18 20:48, lejeczek wrote:
> > hi everyone
> >
> > I've run unetbootin to installed freeDos on a usb stick, which it did,
> > but now my system does not boot. Gee..
> >
> > I have a fedora27 on a Dell laptop in EFI mode.
> > System attempts to boot, where it should do it waits just a few sec and
> > says no bootable devices available, or something like that.
> >
> > I boot a liveCD fedora, there I do:
> > # efibootmgr -v
> > ...
> > Boot0008* f25
> > PciRoot(9x)/Pci(0x17,0x0)/EDD10(0x2a010480)/HD(1,GPT,c9b2adc2-.....,0x800x0x64000/File(\EFI\fedora\grubx64.efi)
> >
> > ...
> >
> > that entry above was, should be my fedora installation. I do:
> > # fdisk -l /dev/sda
> > ...
> > Device....
> > /dev/sda1    2048    411647    4009600    200M EFI System
> > /dev/sda2    411648    1435647    1024000    500M Linux filesystem
> > /dev/sda3    1435648    5000117503    49...    237.8G Linux filesystem
> >
> > So it seems like everything is there, right? I'm really asking, I'm a
> > novice here on grub2/efi subject.
> >
> > I tried mounting /dev/sda1 under /mnt in live fedora, then I did:
> > # grub2-install --efi-directory=/mnt/EFI /dev/sda
> > which command said id did without errors, but all I can see happened a
> > new entry was added which efibootmgr would show, but that new boot id
> > would not boot also.
> >
> > Any help, advice on how to troubleshoot it I'd greatly!! appreciate.
> >
> > many! thank, L.
> >
> > _______________________________________________
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> > https://lists.gnu.org/mailman/listinfo/help-grub
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hi,

first of all I think I should make it into a warning - 
unetbootin (maybe only when you have UEFI boot) does 
something disturbing, it does some damage there thus better 
do not use it - to all who may want to use it.

I did not try to boot to freeDos, first reboot after I used 
netbootin and system failed to boot. The damage was already 
done.

Yes, I looked at /dev/sda1, from Boot0008* f25, the file 
that is referenced there does exist, in that exact path.

Because I could not afford time to investigate it, I had to 
reinstall fedora. But some time I'll let unetbootin do the 
damage again on some spare laptop so I could do some more 
investigation.

thanks, L