Re: [gentoo-user] Recovering MySQL Database from EXT4 Formatted Hard Disk ...

[Christopher Koeber]

On Wed, Feb 8, 2012 at 4:27 PM, Mick <michaelkintzios@×××××.com> wrote:

> On Wednesday 08 Feb 2012 11:33:42 Hinnerk van Bruinehsen wrote:
> > On 08.02.2012 12:02, Michael Mol wrote:
> > > On Tue, Feb 7, 2012 at 6:28 PM, Christopher Kurtis Koeber
> > >
> > > <ckoeber@×××××.com> wrote:
> > >> Hello,
> > >>
> > >> I am trying to recover MySQL databases (which were properly shut
> > >> down) from an EXT4 formatted hard disk.
> > >
> > > What happened to require the recovery? Which parts of the database
> > > server shut down properly, and which didn't?
> > >
> > >> I loaded the SystemRescueCD distro that you can get online and
> > >> when running TestDisk I can see the partitions but I cannot
> > >> recover said partitions because it tells me the structure is bad
> > >> (any options here, by the way?)
>
>
> > You could try Autopsy & sleuthkit[1].
> > Before you do anything to the drive it would be wise to copy it via dd
> > so that no accidental write makes anythoing worse...
> >
> >
> >
> > [1] http://www.sleuthkit.org/autopsy/desc.php
>
>
> Definitely create an image of the partition first, rather than keep
> accessing
> the real thing.  At this moment you don't know what caused the corruption
> - it
> could well be a warning of worse things to come as far as this drive is
> concerned ...  ;-)
>
> It is much better if you create the image with dd-rescue/ddrescue (can't
> recall which of the two packages is claimed to be better).  You may also
> want
> to make a backup copy of the image in case you embark on any destructive
> operations on it.
>
> Multiple passes with ddrescue may recover more bits/bytes so hopefully
> you'll
> have a more complete set of data to work with.
>
>
> > >> With PhotoRec, I can recover parts of the MySQL Database but I
> > >> cannot get the important *.MYD files because I guess PhotoRec
> > >> doesn't have the signatures for that type of file.
> > >>
> > >> So, any options I have at this point?
>
> You can use dd or hexdump to pick up some blocks at the start of a known
> good
> *.MYD file, create a signature for PhotoRec and add it on the list of
> files to
> check for.
>
> See the instruction of how to go about this here:
>
> http://www.cgsecurity.org/wiki/Add_your_own_extension_to_PhotoRec
> --
> Regards,
> Mick
>

Never had a chance to reply back but this was very helpful.

Now to search online to see if people created signatures for "IBD" files
(where the actual data for a MySQL database lives) as the headers are
different for every sample "IBD" I tried from working databases.

Regards,
Christopher Koeber