[Bug 995144] Re: Grub2 Corrupts Hard Drive and Bad Design Causing failed boot.

[Phillip Susi]

Unfortunately there is no such thing as a grub boot partition in the
msdos partition table, and adding one would cause more problems that it
would solve given the fragility of the msdos partition table.  Using the
unpartitioned space after the MBR is the best grub can do on msdos
partitioned disks, and intended behavior, not a bug.  Also there is
nothing particular about the first track that makes it any more or less
safe to use than any other unpartitioned space on the disk.  It is
simply a matter of convention that msdos left this space unpartitioned,
and boot loaders decided to make use of it.

Normally the grub core image can fit within 62 sectors, depending on
what modules are built into it.  It appears that recently when both lvm
and raid modules are built in, it no longer quite fits in 62 sectors.
Fortunately, the convention has shifted in recent years to not start the
first partition until sector 2048.


** Changed in: grub2 (Ubuntu)
       Status: Incomplete => Invalid

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https://bugs.launchpad.net/bugs/995144

Title:
  Grub2 Corrupts Hard Drive and Bad Design Causing failed boot.

Status in “grub2” package in Ubuntu:
  Invalid

Bug description:
  It's bad enough that the designers of various linux distros decided
  the default place for GRUB was the MBR instead of adhering to standard
  PC architecture practices (which all other OSes, including *nix
  version, followed), of putting the kernel loaders in the partition and
  making it active so standard code in the MBR would transfer control to
  it.  For cases where a volume was to boot it could have made the
  Extended partition active, put the start code in the EBR of the
  extended and have that boot the volume.    The Linux community would
  have a fit if MS decided it was going to write its own kernel loaders
  and stick them in the MBR and take over the disk.

  Anyway, now apparently whoever has taken over GRUB2 (latest version)
  has made some big mistakes and must not understand the standard pc
  architecture either.  Someone has made it write outside the first
  track of the hard drive if it doesn't think there is a partition
  there.

  1 - Writing outside the first track of the hard drive can corrupt
  partitions not in the MBR at the time which is common with various
  partitioning schemes and cause data loss for users.

  2 - Adding a partition to the start of the disk (cylinder aligned)
  afterwards would overwrite the part of GRUB written out beyond the
  first track making the entire system unbootable.

  3 - changing partition layouts can again overwrite GRUB data which
  should be in the partition by default.

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