Re: lvm support

[Eric Shattow]

Regarding the LVM patch...

I did not write it.   I merely updated an existing patch to compile 
against a known version of GRUB.

I tested it for LVM1/2, but it only works if the PV is made out of msdos 
label partitions (due to a limitation in GRUB code I think). 
Additionally, GRUB overwrites key areas of the hard disk that are used 
by LVM whole-disk Physical Volumes (PVs).

I would like to see this patch updated to work with a whole-disk (i.e. 
/dev/hda) PV, but there is some question of whether this fits within the 
scope of GRUB or not...

To boot off a whole-disk PV/LVM2 setup GRUB needs to fill the following 
points
- identify non-msdos disk label block devices
- fit within the first 0x200 bytes  (for LVM2; possibly relocate to some 
other part of the drive that is LVM2 safe)
-  initialize a small LVM layer to recognize and identify the physical 
devices that contain data for a given file.  assuming the Logical Volume 
(LVM term here) is contiguous and linear is fine for minimal support, 
and would serve my purpose, but could (should?) be extended for 
non-contiguous file data to provide support for LVM in the various 
"RAID" modes.
- new naming scheme for RAID/LVM devices?: kernel 
<myvolgroup>/boot/linux/vmlinux.img

I think that this patch *should* be applied to grub upstream, but I do 
not know enough about GRUB internals to QA it.  this is probably 
something to consider for GRUB2

it's up to you guys.

cheers,

-Eric


Thomas Schwinge wrote:

> [ CCing to the author of the patch mentioned below, Eric Shattow ]
>
> On Thu, Sep 23, 2004 at 02:46:07PM +0200, Harald Dunkel wrote:
>  
>
> > Hi folks,
> >
> > About 2 years ago somebody posted a patch to add LVM support
> > for Linux to grub (0.92, see bug #977). I don't know why it
> > wasn't included in the CVS tree. Obviously such an extension
> > would be _very_ helpfull.
> >
> > Anyway, today the patch seems to be removed from the mailing
> > list archive. Is there a newer patch anywhere?
> >    
>
> A newer patch is available here:
> <URL:http://bugs.gentoo.org/show_bug.cgi?id=42433>
>
> I don't know if it's working at all - I have not yet tested it.
>
> Eric, could you please comment on this issue?
>
>
> Regards,
> Thomas
>