Hi Emanuel

Thanks for that link. It's OK - I'm not hosting websites on my CentOS 6
box! There are a number of reasons why I've been terrified of trying to
upgrade this box up to now - and the experience of the last fortnight
has tended to confirm most of my existing fears and add a few more
besides. I'm just glad that I decided to take a clone of the hard disk
before starting the upgrade.

If the grub guys have just arbitrarily decided not to support kernel v2,
then it was probably a bit high-handed of them. Red
Hat/CentOS/Scientific Linux/Oracle version 6 was the last version before
systemd'struction, and I suspect that there may be quite a lot of boxes
around still running it.


On Sun, 2022-02-13 at 23:09 +0100, Emanuel Loos via Dng wrote:
> Hello Peter,
>
> looks like someone else is experiencing the same issue (though there
> where no answers yet):
>
> https://www.linuxquestions.org/questions/linux-kernel-70/gnu-grub-version-2-04-you-need-to-load-the-kernel-first-4175707760/
>
> I don't see version 2 of the Linux kernel listed on https://kernel.org/
> so if you are hosting websites there how is this secure? If you want a
> stable kernel, how about a longterm version? How about configuring and
> compiling it yourself so it matches your needs best?
>
> By the way: They are GNU/Linux or GNU+Linux distributions, Devuan calls
> itself a GNU+Linux distribution, Debbian calls itself a GNU/Linux
> distribution. They are all based on the GNU operating system with the
> Linux kernel.
>
> The GNU Project, developing an operating system that's completely free
> software (as in freedom, not free beer), was the start of the free
> software movement, long before Open Source existed, but it doesn't get
> acknowledged that much since companies are okay with the idea of Open
> Source (viewing releasing the source code as a good idea sometimes,
> because it is more profitable), but really don't like the idea of free
> software (viewing the freedom of computer users as a must and not
> granting the four essential freedoms of free software when releasing
> software as something unethical which does harm to society).
>
> Kind Regards
>
> Emanuel Loos
>
> On 2/13/22 10:05 PM, Peter Duffy wrote:
> > I've got an old box running CentOS 6.2 and Windows 7. Without going into
> > details, this box is vital and I use it every day. Finally I decided
> > that I had to bite the bullet and upgrade the linux system, and I
> > decided to go for chimaera.
> >
> > Built a new box from scratch and cloned all the disks, using dd, to
> > fresh HDDs (there are several big data disks in the box). Made another
> > clone of the first disk just for safety's sake, then installed chimaera
> > on free space on the first disk - successful; chimaera and windows 7
> > both booted fine. But CentOS 6.2 wouldn't boot - sometimes automatic
> > reboot, sometimes blank screen and hung box.
> >
> > Switched back to the latest clone disk, which fortunately booted
> > successfully, made a fresh clone of the working disk, then tried again:
> > this time, installed beowulf. Install was successful - and this time
> > devuan, windows 7 and CentOS 6.2 all booted successfully.
> >
> > Took another safety clone of the first disk (I'm beginning to wonder if
> > I've exhausted the world's stock of 2T HDDs) and then upgraded beowulf
> > to chimaera. Upgrade successful. Again, the CentOS 6.2 system wouldn't
> > boot.
> >
> > CentOS 6.2 uses kernel 2.6 - it's possible to upgrade to a later one,
> > but this is frowned upon. I suppose it's based on RedHat and
> > derivatives' policy of setting a base version per distro and then
> > retrofitting updates. (I did once try upgrading to a v4 kernel, and the
> > system became completely unstable.)
> >
> > Removed the primary disk, put in the clone with beowulf installed, and
> > verified that all was still working. Then put the disk with chimaera in
> > another box with identical hardware, and started digging into the
> > problem. Grub on chimaera = 2.04-20; on beowulf = 2.02+dfsg1-20
> > +deb10u4. Booted into chimaera and downloaded the packages for the
> > beowulf grub release (grub2, grub2-common, grub-common, grub-pc, and
> > grub-pc-bin), and used them to downgrade grub on the chimaera system -
> > successful. Rebooted - CentOS 6.2 now boots. Tried going into the grub
> > command line environment on each box, and using the "linux" command to
> > load the 2.6 kernel image: result was in grub 2.02, it works fine, and
> > in 2.04, the box reboots at that point.
> >
> > So current conclusion is that something has happened between grub 2.02
> > and 2.04 which prevents the latter from loading linux v2 kernels. The
> > challenge now is to find out what, and if it's possible to work around
> > it in grub 2.04. (I should say that I originally assumed that the
> > problem was down to moving a disk (or a clone of it) from a non-UEFI
> > environment to a UEFI one - but setting everything in the firmware to
> > "legacy only" didn't have any effect.)
> >
> > Just wondered if anyone had any thoughts and comments (other than why
> > the hell am I still running CentOS 6.2 on this box), before I start
> > rummaging through the grub changelogs. Apologies for the length of this
> > and also if I've missed something obvious. The above is a heavily
> > boiled-down summary of about a fortnight of stress and lost sleep.
> >
> > _______________________________________________
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