[CentOS] 8.2.2004 Latest yum update renders machine unbootable

Sat Aug 1 05:05:58 UTC 2020
Mark LaPierre <marklapier at gmail.com>

On 7/31/20 11:20 PM, Johnny Hughes wrote:
> On 7/31/20 11:24 AM, Alessandro Baggi wrote:
>> Il 31/07/20 13:08, ja ha scritto:
>>> On Fri, 2020-07-31 at 22:35 +1200, Alan McRae via CentOS wrote:
>>>> I am running an Intel x64 machine using UEFI to boot an SSD.
>>>> Installing the latest yum update which includes grub2 and kernel
>>>> 4.18.0-193.14.2.el8_2.x86_64 renders the machine unbootable, blank
>>>> screen where grub should be, no error messages, just hangs.
>>>> After some hours I managed to modify another bootable partition
>>>> (containing older software) and boot it from there.
>>>> After that, I  found out it is a known problem.
>>>> The main point of this message is to make people aware of the problem
>>>> and suggest admins don't run 'yum update' until they understand the
>>>> problem and have a fix at hand.
>>>> See 'UEFI boot blank screen post update' for a solution and directions
>>>> to the redhat article.
>>>> Regards
>>>> Alan
>>> I have been punished by this bug - it is/was very nasty.
>> Me too. Luckily it happened on a test machine.
>> Sorry but seems that those packages were not tested before pushing them
>> in the update repo. Would be great to know what happened to the
>> mainstream chains and how a package like grub reached the update repo
>> when it has serious problem (genuine curiosity but not to blame them).
> Of course it was tested before it was pushed. Obviously this is not a
> problem with every install.  Surely you don't think we push items
> without doing any testing.  Certainly not items as important as this update.
>   The CentOS infrastructure has hundreds of servers, most of them were
> not impacted (as an example). In fact, we seem to have had this happen
> on only one machine in those hundreds so far.  It is a problem, obviously.
> The issue seems to be with the shim package (not the grub or kernel
> packages) and we are currently working with Red Hat on a fix.  This
> issue happened in many Linux OSes and even Windows, not just RHEL and
> CentOS.
> We will push a fix as soon as one is available.
> I would hold off on installing this until we release the new fixes.
>> In my case, the restore procedure reported by RH in case of reboot does
>> not work and reports that the packages are already at the lowest version
>> and that the downgrade is not possibile. I don't know why.

It tanked my machine.  I managed to get it to boot into emergency mode 
where I eventually got it to boot on an old kernel as shown in the paste 
below.  After getting it to boot I used grubby to set the default kernel 
to the oldest one on the machine.  Surprisingly enough neither of the 
two most recent kernels would boot even though the machine was running 
on the second oldest kernel when I ran the update that tanked it.  That 
adds credence to the comment above that the problem was not the new 
kernel since it trashed both the new kernel and the one before.  Both 
were from the same series.  The 147 kernel works but neither of newer 
ones would.

CentOS Linux release 8.2.2004 (Core)

enp5s0 IP Address =

Linux localhost.localdomain 4.18.0-147.8.1.el8_1.x86_64 #1 SMP Thu Apr 9 
13:49:54 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux

  Number of cores = 32
  00:55:13 up  8:37,  1 user,  load average: 0.31, 0.48, 0.44

Adapter: PCI adapter
vddgfx:       +0.83 V
fan1:         771 RPM  (min =    0 RPM, max = 3700 RPM)
temp1:        +45.0°C  (crit = +94.0°C, hyst = -273.1°C)
power1:       31.07 W  (cap = 125.00 W)

Adapter: Virtual device
temp1:        +16.8°C  (crit = +20.8°C)
temp2:        +16.8°C  (crit = +20.8°C)

Adapter: PCI adapter
vddgfx:       +0.72 V
fan1:         768 RPM  (min =    0 RPM, max = 3700 RPM)
temp1:        +39.0°C  (crit = +94.0°C, hyst = -273.1°C)
power1:       30.10 W  (cap = 125.00 W)

    ^ ^  Mark LaPierre
Registered Linux user No #267004