Force disk with old GPT label to be recognized as MBR one

[Виталий Туровец]

Hello there, people!
I have a FreeBSD box with 9.1-RC3 i386 and an interesting HDD.
It was patitioned with GPT and zfs some (long) time ago. After that
the hdd has been completely repartitioned with MBR scheme and one
single freebsd (165) partition and one slice there. It worked fine in
7.2, but now i have to get the data from that slice and when i connect
the hdd to 9.1 box, it finds old corrupt GPT label (i suppose, it's
backup GPT header somewhere in the end of actual disk) and does not
recognize the MBR scheme there.
It sees no freebsd partitions (and one exists there, for sure :) ). So
my question is: how do i force the system to ignore old corrupt GPT
header on this hdd, or how do i remove the header, or is there any
workaround possible?
This is what gpart says about this disk:
[11:54][border][~] # gpart show ada1
=>        34  1250263661  ada1  GPT  (596G) [CORRUPT]
          34         256     1  freebsd-boot  (128k)
         290   838860800     2  freebsd-zfs  (400G)
   838861090   411402605        - free -  (196G)

And this is what fdisk says:
[11:54][border][~] # fdisk ada1
******* Working on device /dev/ada1 *******
parameters extracted from in-core disklabel are:
cylinders=1240341 heads=16 sectors/track=63 (1008 blks/cyl)

Figures below won't work with BIOS for partitions not in cyl 1
parameters to be used for BIOS calculations are:
cylinders=1240341 heads=16 sectors/track=63 (1008 blks/cyl)

Media sector size is 512
Warning: BIOS sector numbering starts with sector 1
Information from DOS bootblock is:
The data for partition 1 is:
sysid 165 (0xa5),(FreeBSD/NetBSD/386BSD)
    start 63, size 1250258562 (610477 Meg), flag 80 (active)
        beg: cyl 0/ head 1/ sector 1;
        end: cyl 1023/ head 14/ sector 63
The data for partition 2 is:
<UNUSED>
The data for partition 3 is:
<UNUSED>
The data for partition 4 is:
<UNUSED>

So fdisk sees everything fine.
Thank you a lot guys!

-- 




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Vitaliy Turovets
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