Re: lvm module can't see USB disks' volume group

[Alexandre Oliva]

On Feb  8, 2017, Alexandre Oliva <address@hidden> wrote:

> 5TB disk, USB enclosure that exposes disk as 512B logical sectors: GRUB2
> can see the (GPT) partition table, but it won't expose the PV contents,
> nor can it access files in a separate 256MB btrfs partition created for
> testing at the very end of the disk.  It can, however, read the GRUB
> core embedded in the boot partition in the beginning of the disk.

I think I figured out what the problem is.  Once I created a filesystem
on a smallish partition closer to the beginning of the disk and copied
boot to it, ls (hd*,gpt*)/boot said it couldn't get the C/H/S for the
disk.

Now I gotta figure out where it's trying to get the info; it could be
from the BIOS, in which case it probably won't get it because the disk
probably won't supply it, or it could be from the boot sector, that I
suppose doesn't have the information because nothing put it there.
Presumably to load the embedded image, it just reads from the first few
blocks, enough to not depend on C/H/S.  Well, I'm guessing a lot here,
but it kind of makes sense to me, given the error I got today and the
others I got earlier.  In the end, I might still be out of luck.

-- 
Alexandre Oliva, freedom fighter    http://FSFLA.org/~lxoliva/
You must be the change you wish to see in the world. -- Gandhi
Be Free! -- http://FSFLA.org/   FSF Latin America board member
Free Software Evangelist|Red Hat Brasil GNU Toolchain Engineer