[Bug-ddrescue] Is ddrescue actually accessing my failing drive?

[Jerome]

Apologies if this is the wrong place to ask for help. I was directed here
after asking this question on the PartedMagic support forum.

A copy of my query (with screenshots of terminal output) can be found here:
http://unix.stackexchange.com/questions/219365/ddrescue-recovering-0b-but-drive-appears-in-device-manager-is-it-failing-to-con

I have a failing hard-drive from a NAS. First sign of trouble came when the
drive showed all its root folders and sub-directories as empty, although
windows (via a mounted share) still displayed the expected disk usage,
about 1.2TB of the full available 1.8TB).

After a bit of research  I came across a guide that recommended first
making a copy of the disk using ddrescue and trying to recover data from
the copy.

I purchased PartedMagic and a second 2TB Seagate Barracuda drive to clone
to.

Running lsblk -o name,label,size,fstype,model confirms the failing drive as
sda and the new drive as sdb

So I tried ddrescue... initially using:

ddrescue -d -f /dev/sda /dev/sdb /media/sdd1/rescue.logfile

(where sdd1 is another usb stick attached to the system to save the logfile
to)

But from the very start, the terminal output shows: 0 B copied, current
rate remains at 0B/s and run time and successful read (time) remain
identical. In other words, as far as I can tell ddrescue never actually
reads a single byte from the failing disk:

I let this run for about two days until the Finished prompt appeared in the
terminal. 0 B copied.

So I then tried partitioning the new drive (with a single ntfs partition,
to match the failing drive) and repeated the process but this time only
cloning the partition:

ddrescue -d -n -f /dev/sda1 /dev/sdb1 /media/sdd1/rescue2.logfile

Same result.

I also tried copying to a disk image

ddrescue -d -n /dev/sda1 /dev/sdb1/drive.img /media/sdd1/rescue3.logfile

Again, after ending at the Finished prompt the drive.img file was 0B.

I then tried different ddrescue options, reading backwards, with and
without direct access, using --force, powering the drive on and off a
number of times (cringe!) each time hoping that it would suddenly start
being read by ddrescue... no luck.

The disk appears in 'Places' with its partition name 'GoFlex Home' so
although I know you're not meant to, someone suggested mounting the drive.
They'd had a similar 0 B problem and found that mounting the drive in read
only mode solved the issue for them. I tried but just got an error telling
me there was an i/o error and that the drive probably has a hardware fault
and can't be mounted.

So... maybe I'm being overly optimistic but I can't see how a drive that is
so badly damaged can appear in File Manager with its partition name intact.
Why can't ddrescue rescue a single byte scanning either forwards or
backwards? I can't quite believe it, I must be doing something wrong but I
don't know what else to try and I don't want to further damage the disk
unnecessarily.

In short, ddrescue completes but recovers 0B although the drive appears in
device manager. Is it really that damaged or is ddrescue failing to connect?

Other forums have suggested booting to Windows and do CHKDSK and trying
sudo dd if=/dev/sda of=./img bs=4k count=4
and see if ./img turns out empty

Do any of you with data recovery expertise recommend doing that? Any help
or advice would be very much appreciated.

Many thanks,

Jerome