Recovering/Restoring Boot Partition

[Chris Murphy]

On Feb 24, 2014, at 8:05 AM, Don Levey <fedora-list at the-leveys.us> wrote:
> I can appreciate that.  If this were a mission-critical machine I might
> be able to justify the setup for a regular, hourly, backup.  At this
> point, though, that seems overkill.  If this hadn't been working before,
> I would probably just accept that it's not going to work and move on.
> Thank you again,

I don't know how a powercut munges the raid metadata on both drives, but the raid isn't running from the info you've provided, and I also don't see evidence of metadata. Two PV's show up instead of one because the raid1 isn't in effect, lvm is seeing them as separate PV's with the same UUID which is why it's confused.

I'm confused how the installer permitted this arrangement because it's supposed to flag the user whenever there isn't enough space for GRUB core.img in the MBR gap - and your setup definitely doesn't appear to have space. The /var/log/anaconda/anaconda.program.log might have a clue in the lines that appear after "grub2-install".

Anyway, make sure you have backups before changing BIOS raid settings. I'd then also make sure the hardware has the latest version of BIOS firmware, and that it also has the current firmware RAID software (it's usually part of utilities offered by the board manufacturer, it could also be a separate package from Intel if it's an Intel implementation). The user space utility in XP I'd like to think offers a way to repair the metadata but you'll have to check the documentation.

Obviously one of the drives is no longer updated since the raid1 is not in effect so it's possible any utility will find the state ambiguous and won't know how to sync the disks, does a overwrite c or does c overwrite a? Consider that this is probably the expected degraded behavior of the array - after all it is still bootable and working. But I don' t know the prescribed method for restoring it from this condition. It might actually be to take a full backup of everything, blow it all away and recreate everything from scratch (raid, system installs, then restore from backups). The idea of raid1 isn't as a backup substitute, it's to improve uptime and in that context it's doing that.


Chris Murphy