Re: Boot from 4TB USB jhard drive

[Emilio Lazo Zaia]

Ok; I'll do all these steps, but before I have a comment:

If I let start the PC with my hard disk (GRUB2) I can insmod lvm, set 
root device to the /boot logical volume on 4KB-sector disk and load the 
GRUB config file. Linux kernel runs and the system on this 4TB USB disk 
starts... But if I set root to this disk (hd1) and chainload the boot 
sector (+1) again it hangs the same way as booting directly to this 4TB 
drive.

On 20/03/16 00:35, Andrei Borzenkov wrote:
> 20.03.2016 07:55, Emilio Lazo Zaia пишет:
> > Hello Andrei.
> >
> > Yes to all your questions!
> >
> > I'm using this 4TB disk on my desktop PC and even on the laptop but booting
> > with another media. Both are BIOS.
> OK, so to make sure we have common ground.
>
> Fetch 2.02~beta3 from http://alpha.gnu.org/gnu/grub
>
> Compile it using
>
> ./configure
> make
>
> Make sure you have mtools and xorriso (could be part of libburnia-tools
> or similar) installed
> Create rescue image that can be used to boot off CD/USB
>
> pkgdatadir=$PWD ./grub-mkrescue -d grub-core -o /tmp/grub.iso
>
> This creates ISO image suitable for both CD and HDD boot. If using USB
> stick, just dd this image on full stick. When booting from it, you will
> end in GRUB command prompt.
>
> Check what
>
> ls -l
>
> in GRUB CLI says. What sector size GRUB detects for your disk? Does GRUB
> see partitions on your disk? Do they look reasonable (size, offset)? If
> yes, try
>
> insmod lvm
> ls -l
>
> again. Does GRUB detect LVs?
>
> Do you have serial port (RS-2323) on your system and another system that
> can be used to connect to serial port? This would make capturing output
> much easier.
>
> > El mar 20, 2016 12:05 a.m., "Andrei Borzenkov" <address@hidden>
> > escribió:
> >
> > > 20.03.2016 02:18, Emilio Lazo Zaia пишет:
> > > > Hello
> > > >
> > > > I'm trying to boot off an WD MyBook 4TB disk (WDC WD40EZRX-00SPEB0) with
> > > > GRUB2. The disk has the following partition schema:
> > > >
> > > > ------
> > > > GPT fdisk (gdisk) version 1.0.1
> > > >
> > > > Partition table scan:
> > > >    MBR: protective
> > > >    BSD: not present
> > > >    APM: not present
> > > >    GPT: present
> > > >
> > > > Found valid GPT with protective MBR; using GPT.
> > > >
> > > > Command (? for help): p
> > > > Disk /dev/sdf: 976746240 sectors, 3.6 TiB
> > > > Logical sector size: 4096 bytes
> > > > Disk identifier (GUID): 117CB10C-C241-460D-AC03-A4F084CFA317
> > > > Partition table holds up to 128 entries
> > > > First usable sector is 6, last usable sector is 976746234
> > > > Partitions will be aligned on 8-sector boundaries
> > > > Total free space is 2 sectors (8.0 KiB)
> > > >
> > > > Number  Start (sector)    End (sector)  Size       Code Name
> > > >     1               8             255   992.0 KiB   EF02 BIOS boot
> > > partition
> > > >     2             256       976746234   3.6 TiB     8E00 Linux LVM
> > > > ------
> > > >
> > > > /boot partition is a logical volume within gpt2 partition. Partition 1
> > > > has "legacy boot" flag. Except the 4KB sector size there is nothing
> > > > strange.
> > > >
> > > > After grub-install the disk boots under kvm with
> > > >
> > > > $ kvm -snapshot -hda /dev/sdf
> > > >
> > > > But in a non virtualized environment it hangs after selecting boot
> > > > device from BIOS boot menu on the laptop (Acer AO722). There is no text,
> > > > only the text cursor.
> > > >
> > > > I've installed lilo and it hangs after "L" and extlinux shows "Multiple
> > > > active partitions" but there is no active partitions on the protective
> > > > MBR and only GPT partition 1 is "legacy boot bootable".
> > > >
> > > > The problem is related to the physical sector size?
> > > That is quite possible. So far I have not heard of BIOS capable of
> > > booting from 4Kn disks and even simply accessing such disks (when
> > > booting from other media) did not work in cases known to me.
> > >
> > > Are you willing to help in debugging it? Do you have possibility to boot
> > > from other, more traditional, media, like CD/DVD or USB stick? Can you
> > > compile GRUB with additional debug print enabled?