bug#33389: parted not recognizing partitions in "non-standard" MBRs with valid partition tables

[Phillip Susi]

Unfortunately to figure out what went wrong would require examining the
partition table, which it appears you have destroyed.  If you happened
to have saved a copy and can provide it, please do so and we can reopen
the bug.

Marc Stenson writes:

> Hello,
>
> While parted 2.3 had no issues with whatever was in the first 446 bytes 
> of the MBR and only looked at the partition table, newer versions such 
> as 3.2 seem to be thrown by unusual boot code (e.g. Grub4DOS) and either 
> show the entire disk as unallocated space or as one big volume/partition 
> with the file system of the first volume. This is despite the partition 
> table being fully compliant and happily read by fdisk and sfdisk.
>
> This may be a "feature" rather than a bug.  Please pardon my ignorance, 
> perhaps newer partition table schemes require the first 446 bits to be 
> parsed. However it could save someone many hours of frustration if this 
> was noted prominently in the documentation.
>
> In my case It was fixed with a simple:
>   dd if=/usr/lib/syslinux/mbr/mbr.bin of=/dev/sdb bs=446 count=1
> after taking the requisite backups and a deep breath.
>
> Thanks and regards,
> Marc