#5 Boot manager writes invalid partition table

open
James Su
None
9
2004-09-21
2004-09-21
No

The Smart BootManager modifies my partition tables (on
all drives) whenever I try to boot an NTFS partition.
It renders the partition table invalid by writing bad
bootable-flags for the NTFS partitions.

The bootable-flag should be either 80h for 'bootable'
or 00h for 'non-bootable'. Instead SBM writes 81h on
the first disk, 82h on the second and so on.

This results in Windows not being able to boot and
Linux not being able to access any partition on that disks.

Repair:
I managed to repair my partition table by getting the
MBR with

dd if=/dev/hda of=mbr bs=512 count=1

and then editing the partition table by hand with a
hex-editor. Then I wrote it back with

dd if=mbr of=/dev/hda bs=512 count=1

When I tried to boot an NTFS partition with SBM again,
I got the same error.

Discussion

  • Robert Kausch

    Robert Kausch - 2004-09-21
    • priority: 5 --> 9
    • assigned_to: nobody --> suzhe
     
  • sunset72

    sunset72 - 2005-12-29

    Logged In: YES
    user_id=1414847

    I saw similar occurence but my linux boot was complaining
    that the /dev/hda5 and 6 are bad. win98 would still boot.
    #fdisk -l
    showed a bootable flag of ?
    #fdisk /dev/hda
    : p
    showed the incorrect bootable flag[?] on a dos/win98
    partition.
    : a
    : 2
    toggled the flag to off.
    : a
    : 2
    toggled the flag to on.
    : w
    write change to partition table
    Now my linux boot gets to chroot to /dev/hda5, but is having
    errors with /dev/hda6 (/home).

    Repeated for the other physical disk, now all OK.

    I was using SBM to allow bootable-cd (eltorito) using info
    gleaned elsewhere; at this stage, do not say yes to the save
    query, also do not save manually, or you'' probably create
    this problem.
    ..sunset.

     
  • Sundar

    Sundar - 2008-10-14

    How can I edit MBR, using which tool? Is it possible to edit the MBR with knoppix? or any other tools, please help. Even I face the same problem, my Windows is not booting after using SBM!!

     
  • Sundar

    Sundar - 2008-10-14

    How can I edit MBR, using which tool? Is it possible to edit the MBR with knoppix? or any other tools, please help. Even I face the same problem, my Windows is not booting after using SBM!!

     

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