Re: Cannot find core.img on a 3Tb GPT usb disk

[lukshuntim]

On Thursday, August 15, 2013 12:22 AM, Chris Murphy wrote:
> On Aug 14, 2013, at 9:50 AM, address@hidden wrote:
> > Sector Sizes:     512 bytes logical, 4096 bytes physical
>
> This indicates it's a 512e drive, but your original post said it had 4096 byte 
> logical sectors.

The 512/4096 logical/physical is seen by smartmontools while the 
4096/4096 is reported by GNU parted and I guess what the smartmontools 
reported is more accurate as it reads the drive directly. I think I just 
accept cgdisk's default when creating the partition for data and the 
partition alignment was 256 sectors. Maybe that's the reason why the 
ef02 BIOS boot partition subsequently created was only allowed to start 
at the rather large value of 1024KiB.

> >   Is it then possible to make BIOS recognise this disk to allow booting?
>
> It should see it as a 512 byte sector drive, so yes if it really has 512 byte 
> logical sectors.

Forgive me for these naive question: will changing the sector alignment 
to a smaller value (using gdisk) make it BIOS bootable? Will such change 
destroy the data on disk? That is, of course, assuming that the 512/4096 
logical/physical information is correct.

> > Can gdisk be used to do the job? If yes, how?
>
> Either gdisk or parted can be used to partition the drive correctly, using GPT 
> partition scheme. However some BIOS have problems with GPT partitioned disks; 
> and other BIOS have problems booting from USB.
>
> > My motherboard is Gigabyte GA-EP43-UD3L rev-1.0 with (Award) BIOS version F9, 
> > if that provides additional useful information.
>
>
> Do you know for sure that this computer can boot from a USB drive? If not I'd test 
> that first, and use MBR partition scheme to eliminate that as a variable. It's 
> also possible it's the combination of USB and GPT that causes the problem, that 
> the BIOS becomes confused with a > 2.2TB drive being reported. You might ask 
> these questions to Gigabyte tech support and see if USB booting of a GPT 
> partitioned 3TB drive is possible.

Yes, I've successfully booted usb devices so BIOS support for usb 
booting is definitely there. I'll try to find out whether the USB GPT 
combination is causing the problem from the vendor. It's not that easy, 
though. Maybe other reader on this list have some experience to share?

Regards,
ST
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