[Nix-dev] Fwd: Grub problem: external pointer tables not supported

Tomasz Czyż tomasz.czyz at gmail.com
Tue Jan 24 05:08:47 CET 2017


Roger,


I got it from my grub.cfg config file. It looks like that's how you access
"root" zfs volume.

If I have

/
/volume1
/volume2

in grub I could access it

$disk/@/
$disk/volume1/
$disk/volume2/

Looks like just a convention but didn't dive into it.

btw, just to clarify my setup, currently I have /boot and /nix/store on the
same zfs volume and works, looks like only one directory is affected by
hardlinks/too many files issue.

Thanks,
Tom

2017-01-24 3:43 GMT+00:00 Roger Qiu <roger.qiu at matrix.ai>:

> Btw what is the `@` symbol mean in your `ls` examples? I've never seen
> that. The grub rescue allows yo use `ls hd (0,1)/...` with no `@`.
> On 24/01/2017 12:52 PM, "Tomasz Czyż" <tomasz.czyz at gmail.com> wrote:
>
>> It looks like I hit some ZFS feature that it's not supported by grub
>> module.
>>
>> How I found that?
>> In grub, you can list files in zfs volumes by doing ``ls $drive/@/home``
>> etc.
>> I could list ``ls $drive/@/nix`` or ``ls $drive/@/nix/var`` but not ``ls
>> $drive/@/nix/store`` where I kept the kernels.
>>
>> I found some explanations about lot's of files and lot's of hardlinks
>> (nix store had at that time more than 130G and probably triggered the
>> feature).
>>
>> nix-collect-garbage -d didn't help.
>>
>> I solved the problem by using boot.loader.grub.copyKernels = true;
>>
>> Kernels were copied to the same volume but to /boot where there is
>> smaller number of files and worked perfectly.
>>
>>
>> 2017-01-23 16:44 GMT+00:00 Tomasz Czyż <tomasz.czyz at gmail.com>:
>>
>>>
>>>
>>> 2017-01-23 16:15 GMT+00:00 Roger Qiu <roger.qiu at matrix.ai>:
>>>
>>>> Hey,
>>>>
>>>> Changing nixos generations won't affect the grub boot partition, that
>>>> only changes which nixos kernel and initramfs image gets booted.
>>>>
>>> Because all boot options are not working one of my guesses is that in
>>> new nix version, wrong config was generated when I did system update which
>>> broke all options.
>>>
>>>> This looks like an error in the Grub partition. Maybe you recently
>>>> updated it or changed it, or the partition got corrupted.
>>>>
>>> It's possible, I tried to boot from USB, do ``nixos-install
>>> --no-root-passwd`` to reinstall the system, but I'm not sure how to force
>>> grub/uefi partition recreation/reinstalling, any idea? Should I just format
>>> it and will be recreated?
>>>
>>>> This is why other operating systems tend to make their /boot
>>>> read-only...
>>>>
>>>> If you can't get into the OS, then you can try booting off a USB, and
>>>> then edit the boot partition. Or run the uefi terminal app (but this one
>>>> never worked for me). If you had cloned/raided boot partitions you can try
>>>> changing the uefi image to boot from in your uefi settings (access it like
>>>> BIOS).
>>>>
>>> I tried that, but I'm not sure what to change. I tried to reinstall grub
>>> on EFI partition but I'm not sure how to do that, is regular grub-install
>>> stuff way to go (I thought I had some issues with that and I tried
>>> nixos-install after that).
>>>
>>>> Currently I have 2 uefi boot partitions cloned, but one failed so I've
>>>> been booting off the other one.
>>>>
>>> Nice one, I think I'll try to do something like that.
>>>
>>> Thanks Roger.
>>>
>>>> Thanks,
>>>> Roger
>>>> On 23/01/2017 10:48 PM, "Tomasz Czyż" <to <tomasz.czyz at gmail.com>
>>>>
>>>
>>>
>>>> masz.czyz at gmail.com <tomasz.czyz at gmail.com>> wrote:
>>>>
>>>>> Hello,
>>>>>
>>>>> recently my grub said this to me after I restarted computer:
>>>>>
>>>>> Error: external pointer tables not supported
>>>>> Error: you need to load the kernel first.
>>>>>
>>>>> Every option I select with nix (also past generations) shows me this
>>>>> message.
>>>>>
>>>>> I updated the system to 17.03pre99792.c311871 on 2016-12-23 and
>>>>> restarted it before multiple times (and worked). I don't remember if I did
>>>>> other updates, but this is what's grub menu shows me.
>>>>>
>>>>> My disk layout is: EFI boot partition for grub, next partition is
>>>>> encrypted luks volume and ZFS on top of it.
>>>>>
>>>>> This setup worked for me for 1.5 year now without any issue.
>>>>>
>>>>> Anybody is aware of any changes to grub/zfs recently or had same issue?
>>>>> Any suggestions how I can recover from it or what can be wrong?
>>>>>
>>>>> Tom
>>>>>
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> nix-dev mailing list
>>>>> nix-dev at lists.science.uu.nl
>>>>> http://lists.science.uu.nl/mailman/listinfo/nix-dev
>>>>>
>>>>>
>>>
>>>
>>> --
>>> Tomasz Czyż
>>>
>>
>>
>>
>> --
>> Tomasz Czyż
>>
>> _______________________________________________
>> nix-dev mailing list
>> nix-dev at lists.science.uu.nl
>> http://lists.science.uu.nl/mailman/listinfo/nix-dev
>>
>>


-- 
Tomasz Czyż



-- 
Tomasz Czyż
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