CentOS - May 2018 - CentOS6: HELP! EFI boot fails after replacing disks...

On 05/29/2018 06:33 AM, Robert Heller wrote:
>
>> The UUID in the EFI boot options is
99E275E7-75A0-4B37-A2E6-C5385E600CB, which
>> does not to match anything, but the system is only happy booting the
old
>> disk...
> And at this point, it will only boot in legacy mode off the old disk.
That's what I meant, I think.? Legacy mode is BIOS-compatible.? If 
you're booting in legacy mode, you can't access the UEFI variables. The 
old disk probably has GRUB installed on the first block.? It might be 
booting in legacy mode *because* the UEFI boot option's UUID doesn't 
match your partition.

You might want to disable legacy mode entirely.? Boot a rescue disk if 
needed, and fix the boot option from there.

At Tue, 29 May 2018 06:47:06 -0700 CentOS mailing list <centos at
centos.org> wrote:
> 
> On 05/29/2018 06:33 AM, Robert Heller wrote:
> >
> >> The UUID in the EFI boot options is
99E275E7-75A0-4B37-A2E6-C5385E600CB, which
> >> does not to match anything, but the system is only happy booting
the old
> >> disk...
> > And at this point, it will only boot in legacy mode off the old disk.
> 
> That's what I meant, I think.?? Legacy mode is BIOS-compatible.?? If 
> you're booting in legacy mode, you can't access the UEFI variables.
The
> old disk probably has GRUB installed on the first block.?? It might be 
> booting in legacy mode *because* the UEFI boot option's UUID
doesn't
> match your partition.
OK,  I think at this point it is not wanting to even boot the old disk in EFI 
mode.  Maybe because the old disk is no longer in SATA port 0 (/dev/sda).  It 
is not wanting to boot the new disk in EFI mode and won't boot from the 
Optical disk in EFI mode (at least I cannot figure out how to do that).
> 
> You might want to disable legacy mode entirely.?? Boot a rescue disk if 
> needed, and fix the boot option from there.
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>                                                                        
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Robert Heller wrote:
> At Tue, 29 May 2018 06:47:06 -0700 CentOS mailing list <centos at
centos.org>
> wrote:
>> On 05/29/2018 06:33 AM, Robert Heller wrote:
>> >
>> >> The UUID in the EFI boot options is
>> >> 99E275E7-75A0-4B37-A2E6-C5385E600CB, which
>> >> does not to match anything, but the system is only happy
booting the
>> >> old disk...
>> > And at this point, it will only boot in legacy mode off the old
disk.
>>
>> That's what I meant, I think.'?'? Legacy mode is
BIOS-compatible.'?'? If
>> you're booting in legacy mode, you can't access the UEFI
variables. The
>> old disk probably has GRUB installed on the first block.'?'? It
might be
>> booting in legacy mode *because* the UEFI boot option's UUID
doesn't
>> match your partition.
>
> OK,  I think at this point it is not wanting to even boot the old disk in
> EFI mode.  Maybe because the old disk is no longer in SATA port 0
(/dev/sda).
> It is not wanting to boot the new disk in EFI mode and won't boot from
the
> Optical disk in EFI mode (at least I cannot figure out how to do that).
<snip>
Y'know, what you just wrote above... that makes it sound like you need to
go into the BIOS and reset the boot order.

      mark