FC4t2 no good without LILO

Peter Jones pjones at redhat.com
Tue Apr 12 18:30:44 UTC 2005

On Tue, 2005-04-12 at 12:25 -0400, Joshua Baker-LePain wrote:
> On Tue, 12 Apr 2005 at 10:06am, pjones at redhat.com wrote
> > If you've got some specific problem with grub, and it's not already
> > filed, file it as a bug.  If it is already reported, read the bug report
> > carefully, and think hard about if you can add any data that would be
> > useful in fixing the problem.
> Here's a question -- does grub work yet if your boot device is >2TB?

Yes, no, and maybe.  It depends on how you partition, and we don't yet
do GPT partitioning; that's an installer bug and an fdisk/parted bug as
much as anything else.  Somebody's been threatening to send me a box to
use to fix it, but nothing has shown up yet.  I'll start coding it blind
at some point, I guess...

> I just ran into this issue on RHEL4.  sda on my system is a ~3TB hardware 
> RAID5 (3ware).  I put a couple of small partitions at the beginning of the 
> disk for /, /var, and the like, the install seemed to go fine, but 
> afterward it wouldn't boot.  Booting into rescue mode and trying commands 
> from the grub prompt seems to indicate that the disk is too big for grub.
> A simple 'lilo' in rescue mode made the system bootable.

I haven't read through the grub code for this stuff in a while, so I
could be off by a little bit about precisely what grub does in this
situation.  I *think* it'll refuse to install if it sees a drive that
*cannot* be partitioned correctly, which is probably actually the case
you're seeing.

lilo's install code doesn't check for things like that, and I could put
forward a pretty good argument for that being a bug or not being one,
either way.

Frankly, though, we lack support for very large disks throughout much of
our userland and installer.  I'm not sure how kernel support for correct
partitioning of many-TB disks is; I recall that it exists but I haven't
tried it.

I really don't think grub-install should touch the disk when it knows
for sure that something is severely amiss.  I think telling you no is
the right behavior unless it sees GPT (which it currently doesn't
support, but neither does the rest of the installer, nor lilo).

You'll probably notice things like the partition getting shorter and
other craziness like that when you reboot, btw, because the size of the
disk overflows the "size" field on your partition table.  Without GPT,
you just can't write a partition table entry with sectors above that


More information about the test mailing list