Re: Boots to grub and references non-existent hd1

[Andrei Borzenkov]

В Wed, 25 Feb 2015 10:51:12 -0800 (PST)
address@hidden пишет:

> 
>  
> -----Original Message-----
> From: "Andrei Borzenkov" <address@hidden>
> Sent: Wednesday, February 25, 2015 10:08am
> To: address@hidden
> Cc: address@hidden
> Subject: Re: Boots to grub and references non-existent hd1
> 
> 
> 
> В Wed, 25 Feb 2015 09:42:49 -0800 (PST)
> address@hidden пишет:
> 
> > - - - - - - - -
> > Ok, here is what I get for those queries.
> > grub> ls (lvm/vg_jab-lv_mintroot)/
> > error: unknown filesystem.
> > 
> ...
> > 
> > I am guessing the unknowns are a problem, but I don't know why they are 
> > unknown, nor what to do about them.
> >
> 
> This means grub image does not include XFS driver so it of course
> cannot load your kernels.
> 
> This image is shipped by your distribution. You need to complaint to
> them. You may install using different filesystem for /boot but you
> still need to know which filesystems are supported.
> 
> Alternative is to somehow disable secure boot support during
> installation. Again, how and whether it will help can be answered only
> by your distribution. openSUSE would in this case skip pre-built image
> and use standard grub-install which should work. What your distro does
> I do not know.
>  
> - - - - - - - - - -
>  
> Ok, I assume that means that grub is not loading the XFS module, and when I 
> do an lsmod at the grub prompt I don't see the XFS module listed.  However, 
> when booting from the SuperGrub2CD menu list (which I assume must be loading 
> the XFS module) and looking in the /boot/grub/x86_64-efi directory I do see 
> the xfs.mod file present.  And when I go through the Mint installer, it 
> provides the option to use the XFS filesystem.  So, from that I would 
> conclude that the Mint distribution supports it; but maybe their grub-install 
> is broken with respect to importing the XFS module?  (that is an actual 
> question, since I don't want to speculate beyond my knowledge.  I am just 
> trying to figure out how to clarify or specify a request that I can put to 
> the Mint distribution).

Distributions that support EFI secure boot ship pre-built image so they
can sign it (you cannot sign something that is created on end-user
system) and disable module loading (because modules cannot be
signed ... OK they can but nobody right now does it). So grub can
support only those filesystems that have drivers included in pre-built
image. It never loads modules from disk (even if it could - it cannot
in your case).

Because your boot menu refers to shim, it is strong indication that
your system is setup for EFI secure boot (shim provides common
implementation of EFI signature check).

Normal grub-install builds grub image on the fly and includes all
modules needed to access /boot/grub. All other modules are then loaded
dynamically as needed from /boot/grub.

>  
> Looking at lsmod again I see that the ext2 module is loaded, so maybe I will 
> try another re-install setting my boot partition to EXT2, although I would 
> much prefer to have it on a journaled filesystem, but I don't see an ext3 or 
> ext4 module listed in the /boot/grub/x86_64-efi directory.  Are they named 
> something different that might not be obvious?

grub2 ext2 module supports all flavors of ext* filesystems (some brand
new features could be still unsupported though; I tend to recommend ext2
for /boot to be on safe side).