Chris,
Thank you for your help.
I had to re-create the initramfs as well and, change fstab too. The process was up hill in
both directions... due to my fumbling. Sigh.
I now have a VM FC34 x86_64 (Rawhide) running with btrfs file systems.
After a few upgrades I did an "init 0" command. The VM didn't close so I
checked the console. Something was spewing messages concerning "access beyond
device". Nothing was logged in /var/log/messages or other files. WTF? The VM is
running under VirtualBox but nothing was logged there either. I'm watching for the
error if it happens again. Your thoughts would be appreciated.
Again, thanks for ALL your help.
George...
On Wednesday, September 2, 2020, 2:48:55 PM PDT, Chris Murphy
<lists(a)colorremedies.com> wrote:
On Wed, Sep 2, 2020 at 3:42 PM George R Goffe via test
<test(a)lists.fedoraproject.org> wrote:
Hi,
I'm playing around with FC34 ina VM and have backed up /boot; put a btrfs fs on the
partition; restored from the backup, updated fstab but grub2 still goes into rescue mode.
This tells me that there's something I don't know which is entirely possible.
Could it be a missing driver in the initfs (name btrfs)?
Is there a quick answer? Can I get some doc links to rtfm? Please?
Yes the UUID of /boot has changed, so grub.cfg is looking for the
wrong grub root (which is normally /boot).
BIOS firmware you need:
grub2-install /dev/sdX - whatever is the whole drive block device.
This adds a btrfs driver to GRUB core.img so it can read /boot
grub2-mkconfig -o /etc/grub2.cfg - this will add the UUID of /boot
UEFI firmware you need just the 2nd command but it needs to be
/etc/grub2-efi.cfg
Their real locations are:
ls -l /etc
...
lrwxrwxrwx. 1 root root 22 Aug 21 08:30 grub2.cfg ->
../boot/grub2/grub.cfg
lrwxrwxrwx. 1 root root 31 Aug 21 08:30 grub2-efi.cfg ->
../boot/efi/EFI/fedora/grub.cfg
Make sure whether you have UEFI or BIOS though. One way is run
efibootmgr. If there's an error, it's BIOS. If multi-line output it's
UEFI. You do not want to run grub-install on UEFI.
--
Chris Murphy