EFI variables are not supported on this system

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1

Infamous Windows 10 Features Updatte, grub menu disappeared. I have had this before with previous windows installations, but I am fighting this one. I followed instructions to boot UEFI from a thumb drive with Fedora 31KDE spin . I then performed the following.

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**pertinent parts of fdisk -l**
[root@localhost-live liveuser]# fdisk -l
Disk /dev/sda: 119.25 GiB, 128035676160 bytes, 250069680 sectors
Disk model: SK hynix SC311 S
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disklabel type: gpt
Disk identifier: 28503AE9-8383-4F29-A394-BA9FB4617722

Device Start End Sectors Size Type
<b>/dev/sda1 2048 1333247 1331200 650M EFI System</b>
/dev/sda2 1333248 1595391 262144 128M Microsoft reserved
/dev/sda3 1595392 137233033 135637642 64.7G Microsoft basic data
/dev/sda4 137234432 138321919 1087488 531M Windows recovery environment
**/dev/sda5 138323968 142229503 3905536 1.9G EFI System**
/dev/sda6 142229504 209567743 67338240 32.1G Linux LVM
/dev/sda7 209567744 220243967 10676224 5.1G Linux filesystem
/dev/sda8 221181952 247832575 26650624 12.7G Windows recovery environment
/dev/sda9 247834624 250068991 2234368 1.1G Windows recovery environment

Disk /dev/mapper/fedora_localhost--live-home: 19.102 GiB, 21470642176 bytes, 41934848 sectors

Disk /dev/mapper/fedora_HDD1TB-var: 46.58 GiB, 50000297984 bytes, 97656832 sectors

Disk /dev/mapper/fedora_localhost--live-root: 17.2 GiB, 18467520512 bytes, 36069376 sectors

Disk /dev/mapper/fedora_HDD1TB-usrshare: 20 GiB, 21474836480 bytes, 41943040 sectors

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Commands

[root@localhost-live liveuser]# mkdir -p /mnt/root
[root@localhost-live liveuser]#
[root@localhost-live liveuser]# mount /dev/mapper/fedora_localhost--live-root /mnt/root
[root@localhost-live liveuser]# mount /dev/mapper/fedora_HDD1TB-var /mnt/root/var/
[root@localhost-live liveuser]# mount /dev/mapper/fedora_HDD1TB-usrshare /mnt/root/usr/share/
[root@localhost-live liveuser]# mount /dev/sda5 /mnt/root/boot/efi/
[root@localhost-live liveuser]# mount -o bind /dev /mnt/root/dev
[root@localhost-live liveuser]# mount -o bind /proc /mnt/root/proc
[root@localhost-live liveuser]# mount -o bind /sys /mnt/root/sys
[root@localhost-live liveuser]# mount -o bind /run /mnt/root/run
[root@localhost-live liveuser]#

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[root@localhost-live liveuser]# chroot /mnt/root
[root@localhost-live /]# grub2-mkconfig -o /boot/efi/EFI/fedora/grub.cfg
Generating grub configuration file ...
grub2-probe: error: cannot find a GRUB drive for /dev/sdc1. Check your device.map.
grub2-probe: error: cannot find a GRUB drive for /dev/sdc3. Check your device.map.
File descriptor 3 (pipe:[74164]) leaked on vgs invocation. Parent PID 8016: grub2-probe
File descriptor 9 (pipe:[76155]) leaked on vgs invocation. Parent PID 8016: grub2-probe
File descriptor 3 (pipe:[74164]) leaked on vgs invocation. Parent PID 8016: grub2-probe
File descriptor 9 (pipe:[76155]) leaked on vgs invocation. Parent PID 8016: grub2-probe
File descriptor 3 (pipe:[74164]) leaked on vgs invocation. Parent PID 8079: grub2-probe
File descriptor 9 (pipe:[76155]) leaked on vgs invocation. Parent PID 8079: grub2-probe
File descriptor 3 (pipe:[74164]) leaked on vgs invocation. Parent PID 8079: grub2-probe
File descriptor 9 (pipe:[76155]) leaked on vgs invocation. Parent PID 8079: grub2-probe
File descriptor 3 (pipe:[74164]) leaked on vgs invocation. Parent PID 8230: grub2-probe
File descriptor 9 (pipe:[76155]) leaked on vgs invocation. Parent PID 8230: grub2-probe
File descriptor 3 (pipe:[74164]) leaked on vgs invocation. Parent PID 8230: grub2-probe
File descriptor 9 (pipe:[76155]) leaked on vgs invocation. Parent PID 8230: grub2-probe
Found Windows Boot Manager on /dev/sda1@/efi/Microsoft/Boot/bootmgfw.efi
done

[root@localhost-live /]# echo $?
0

[root@localhost-live /]# stat /boot/efi/EFI/fedora/grub.cfg
File: /boot/efi/EFI/fedora/grub.cfg
Size: 6620 Blocks: 16 IO Block: 4096 regular file
Device: 805h/2053d Inode: 476 Links: 1
Access: (0755/-rwxr-xr-x) Uid: ( 0/ root) Gid: ( 0/ root)
Access: 2020-02-22 23:00:00.000000000 -0500
Modify: 2020-03-27 12:52:16.000000000 -0400
Change: 2020-03-27 12:52:17.690000000 -0400

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So far, so good. Then the trouble begins

[root@localhost-live /]# grub2-install /dev/sda
Installing for x86_64-efi platform.
File descriptor 4 (/dev/sda5) leaked on vgs invocation. Parent PID 8775: grub2-install
File descriptor 4 (/dev/sda5) leaked on vgs invocation. Parent PID 8775: grub2-install
EFI variables are not supported on this system.
grub2-install: error: efibootmgr failed to register the boot entry: Unknown error 21897.
[root@localhost-live /]#
===

I’ve tried a few variations that I found suggested on different forums, but none are successful.

GRUB BORKED, HELP!

Thanks
JimR

2

Turned out that I had to go into Setup and created a new UEFI boot to load the correct grub module, gcdx64.efi from my SDA5 volume. It took a lot of experimenting and wrong turns to get there, but I finally got it back, and all is right with the world. I have not re-tried Windows 10 yet, and I almost don’t care!

2 Likes
3

I had a similar issue when I first installed fedora as dual boot with windows using UEFI.
I also created a second EFI partition as you did for the fedora install but could only boot one OS.

My simple fix was to reinstall fedora, but instead of using 2 EFI partitions I told it to use the original microsoft EFI partition with only one EFI partition on the disk and it dual boots flawlessly.

I have since seen posts by others that are able to use multiple EFI partitions, but for myself the single EFI works so why change?

4

This is a mature installation, and is my personal business machine. It probably goes back to at least Fedora 26 since I last did a full install. The collective wisdom at that time was to build a 2nd EFI partition for Linux.

Knowing Windows penchant for wanting to own my machine, I think it wise to keep my Fedora installation as separate as possible. Think of it as “Social Distancing”

5

LOL
Yep, and both methods do work.
A single EFI partition seemed simpler for me then (I think around F24) and I have not tried it any different since.

The EFI partition format is the same, and since the microsoft bootloader does not interfere with fedora and vice-versa I just left it.

6

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