[mythtv-users] Hard drive failure -- recovery method suggestions

[Jerry]

On Mon, Apr 27, 2015 at 12:10 PM, Stephen Worthington <
stephen_agent at jsw.gen.nz> wrote:

>
> The errors being reported are likely for an attempt to read the master
> boot record (MBR) where the partition table is stored.  If the MBR is
> unreadable, that is not fatal to data recovery, but it sure does not
> help.  If it is a head crash that has killed the track the MBR is on,
> then the rest of the disk can be OK, but will likely be unreadable as
> the head is damaged.  It would be worth trying using dd to read a few
> random locations further up the disk.  If you try that, listen
> carefully to see if you can hear the click or buzz sound of the heads
> moving - if they do not move, there is no hope for reading anything.
>
> I believe modern drives actually store some hidden data about
> themselves on the disk somewhere, including a serial number, various
> settings and encryption keys for encrypted drives.  It sounds like the
> controller is unable to read that data correctly now, hence the wrong
> drive size being reported.  So my guess would be that you will find no
> sectors able to be read anywhere, with the problem being in the head
> or the electronics.  If so, the only way that recovery is likely now
> is through a professional firm that has specialised equipment (eg they
> could move the disk platters themselves to another drive to be read).
> But that is pretty expensive.
>
> To check if the drive really is unable to read its identity data, use
> the command "smartctl -i /dev/sd<x>" on it - it should be able to
> report the drive type, size and serial number and so on.  It should
> look something like this:
>

<snip>


> It might still be worthwhile cooling the drive in the fridge to see if
> that helps - at this point, there would seem to be little chance that
> anything you try would make the damage worse.  But the cooling trick
> is normally for bearings that are going, and what you have does not
> have the right symptoms for that.
>

Here is the result of that command.  It appears that the drive now is 137
GB, so it grew a little bit overnight (from 4.1 GB) :)

[root at htpc ~]# smartctl -i /dev/sdd
smartctl 6.2 2014-07-16 r3952 [x86_64-linux-3.19.5-200.fc21.x86_64] (local
build)
Copyright (C) 2002-13, Bruce Allen, Christian Franke, www.smartmontools.org

=== START OF INFORMATION SECTION ===
Device Model:     ST3000DM001
Serial Number:    <serial number>
LU WWN Device Id: 5 000c50 04edd0b44
Firmware Version: CC29
User Capacity:    137,438,952,960 bytes [137 GB]
Sector Size:      512 bytes logical/physical
Rotation Rate:    7200 rpm
Device is:        Not in smartctl database [for details use: -P showall]
ATA Version is:   ATA8-ACS T13/1699-D revision 4
SATA Version is:  SATA 3.0, 6.0 Gb/s
Local Time is:    Tue Apr 28 09:15:33 2015 EDT
SMART support is: Available - device has SMART capability.
SMART support is: Enabled

I haven't put it in the refrigerator yet.

Thanks for you continued help.

Jerry
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