Error: symbol "grub is lockdown" not found boot error (solved)

[SeanK]

Hi All,

Running a Debian Buster derivative Q4OS. All was well until the weekend when it spat the dummy on start up:

error: symbol 'grub_is_lockdown' not found.
Entering rescue mode...
grub rescue>

Does anyone know how to fix this? Any advice appreciated.

 

[captain-sensible]

There are different approaches , the worst case scenario being fresh install ..

IS your motherboard 64 bit UEEFI do you know ?

If so AND IF you can get rEFInd http://www.rodsbooks.com/refind/getting.html onto a usb http://sourceforge.net/projects/refind/files/0.13.1/refind-flashdrive-0.13.1.zip/download



abd boot from usb, via appropriate key at boot up it might be able to get an os up and running. I've tried it to boot Windows 10 and slackware it works.


Out of interest single install of Linux OS only or dual boot with Windows ?



Also At : grub rescue >

type

 ls

and see what it outputs




if you get any output , that would be a good sign. then it will be a case of manually telling your system where initial boot ram and vmlinuz is et cetera - at least that is how it works with slackware.


Another way if you have live OS handy would be to boot from usb, use it to mount your PC root install partition , then chroot that partition. So commands from terminal usb , of OS on usb stick would be evoking on your main PC. You then could try re-install grub2 and also run update-grub

i'm sure you will get several replies


just remembered another one - super grub rescue disk thingy - i've got an iso on usb stick formatted with ventoy


super_grub2_disk_hybrid_2.04s1.iso

 

[SeanK]

There are different approaches , the worst case scenario being fresh install ..

IS your motherboard 64 bit UEEFI do you know ?

If so AND IF you can get rEFInd http://www.rodsbooks.com/refind/getting.html onto a usb http://sourceforge.net/projects/refind/files/0.13.1/refind-flashdrive-0.13.1.zip/download



abd boot from usb, via appropriate key at boot up it might be able to get an os up and running. I've tried it to boot Windows 10 and slackware it works.


Out of interest single install of Linux OS only or dual boot with Windows ?



Also At : grub rescue >

type

ls

and see what it outputs




if you get any output , that would be a good sign. then it will be a case of manually telling your system where initial boot ram and vmlinuz is et cetera - at least that is how it works with slackware.


Another way if you have live OS handy would be to boot from usb, use it to mount your PC root install partition , then chroot that partition. So commands from terminal usb , of OS on usb stick would be evoking on your main PC. You then could try re-install grub2 and also run update-grub

i'm sure you will get several replies


just remembered another one - super grub rescue disk thingy - i've got an iso on usb stick formatted with ventoy


super_grub2_disk_hybrid_2.04s1.iso

Many thanks for the advice. Its an intriguing little problem I have not seen before. Using "ls" yields:

(hd0) (hd0, gpt3) (hd0, gpt2) (hd0, gpt1)

I can still access the OS and load it by choosing q4os from the boot manager after resetting the system and pressing F9. Everything still works on loading. Its just a bit of a nuisance having these extra steps as you can appreciate.

I'll take a look at some of those options you present and see what I can do. Bit time pressured right now as I'm selling our main house so might just opt for a fresh install. Its my mini laptop I use when I'm away from home and not my primary laptop so not shedding any tears over lost information (which is backed up anyway).

 

[SeanK]

There are different approaches , the worst case scenario being fresh install ..

IS your motherboard 64 bit UEEFI do you know ?

If so AND IF you can get rEFInd http://www.rodsbooks.com/refind/getting.html onto a usb http://sourceforge.net/projects/refind/files/0.13.1/refind-flashdrive-0.13.1.zip/download



abd boot from usb, via appropriate key at boot up it might be able to get an os up and running. I've tried it to boot Windows 10 and slackware it works.


Out of interest single install of Linux OS only or dual boot with Windows ?



Also At : grub rescue >

type

ls

and see what it outputs




if you get any output , that would be a good sign. then it will be a case of manually telling your system where initial boot ram and vmlinuz is et cetera - at least that is how it works with slackware.


Another way if you have live OS handy would be to boot from usb, use it to mount your PC root install partition , then chroot that partition. So commands from terminal usb , of OS on usb stick would be evoking on your main PC. You then could try re-install grub2 and also run update-grub

i'm sure you will get several replies


just remembered another one - super grub rescue disk thingy - i've got an iso on usb stick formatted with ventoy


super_grub2_disk_hybrid_2.04s1.iso

Oh and its not a dual boot with another OS.

 

[captain-sensible]

when you get time , it would be worth carrying on with : (hd0) (hd0, gpt3) (hd0, gpt2) (hd0, gpt1) so that you have up your sleeve how to boot an OS from grub> or grub rescue >

from that i think you have one none sata old style hard disk and three partitions , since from memory , at least with grub2 disks start from Zero but partitions now start at one. i'm guessing efi, swap and main install partition . Output of sudo lsblk or fdisk -l might clarify that .


so from grub rescue next command to try might be :

ls (hd0,gpt3)

Following on from , you mentioning you can actually boot OS then in theory it should just be a case of trying to re-install grub and maybe update (update-grub)

my partition of root install slackware is /dev/sda3 so to install grub2 all i did was as #:

grub-install /dev/sda3

 

[SeanK]

when you get time , it would be worth carrying on with : (hd0) (hd0, gpt3) (hd0, gpt2) (hd0, gpt1) so that you have up your sleeve how to boot an OS from grub> or grub rescue >

from that i think you have one none sata old style hard disk and three partitions , since from memory , at least with grub2 disks start from Zero but partitions now start at one. i'm guessing efi, swap and main install partition . Output of sudo lsblk or fdisk -l might clarify that .


so from grub rescue next command to try might be :

ls (hd0,gpt3)

Following on from , you mentioning you can actually boot OS then in theory it should just be a case of trying to re-install grub and maybe update (update-grub)

my partition of root install slackware is /dev/sda3 so to install grub2 all i did was as #:

grub-install /dev/sda3

Thanks so much. I have to confess I did a quick install but its worth noting in case this re-occurs at some point.