Re: [Bug-ddrescue] Having trouble mounting ddrescue image

[andrew zajac]

The fact that you imaged the partition only as well as the fact that you used a usb interface is not a problem.  In fact, in the case of a drive that keeps disappearing, using a USB interface will avoid you the trouble of having to reboot every time.

You need to complete the image of the partition.  That's the only problem here - that's why the NTFS filesystem won't mount.  Continue to run ddrescue using your existing image and logfile.  As mentioned, don't use the no-split option.

If ddrescue is not able to complete without any error spots left, it may be that the data is no longer be there, but if that's the case, it's not your fault.  The damage is already done.

Regards,

Andrew Zajac


--- On Tue, 2/1/11, Ian Oliver <address@hidden> wrote:

From: Ian Oliver <address@hidden>
Subject: Re: [Bug-ddrescue] Having trouble mounting ddrescue image
To: address@hidden
Received: Tuesday, February 1, 2011, 5:29 AM

In article <address@hidden>, Lonestarshack wrote:
> The drive automounted once it was discovered and then I was able to
> run ddrescue on just the main NTFS partition that was on the drive.

You're much better running ddrescue without the drive mounted. The OS tends to
keeps accessing the drive, particularly if it's retrying bad sectors, and this
just makes life harder for ddrescue. ddrescue hits the device directly,
doesn't need the drive to be mounted, so unmount it.

> I DID
> NOT run ddresuce on the entire drive; just the NTFS partition I want to
> recover.

Sensible, but can make it harder to restore to a new drive.

> Due to problems with the hard drive, sometimes the drive would
> unmount on its own. At that point, ddrescue would stop.

Sounds like the drive is having serious problems. Is it attached via SATA or
USB? I've had problems with USB connected drives in the past as the error
handling on USB seems iffy with some bridges.

> So, since I was
> using the log file option, I simply reattached the drive, it automounted,
> and I continued with creating the image.

As soon as the OS mounts the drive, unmount it. Even this didn't work for me
once, and I ended up using a Puppy Linux LiveCD as this doesn't touch drives
until you tell it to.

> Now, no
> matter what I try to do, I can't seem to get this drive to mount. Here's an
> fdisk output on the image which doesn't look good to begin with. Any
> thoughts from the ddrescue wizards out there?
>
> address@hidden internal]# losetup -r /dev/loop0 01.img
> address@hidden internal]# fdisk -lu /dev/loop0

The loop mount looks right, but fdisk won't work on just a partition: it needs
to see a partition table.

Your options are,
1) Image the whole disk, fdisk will work, losetup will need an offset to the
right partition if you're to mount it.
2) Image just one partition, losetup won't need an offset, fdisk won't work.
This is your case.

# Command line: ddrescue --verbose --no-split /dev/sdd1
/media/9edd991c-2497-4f92-aa86-bf6ccf9ddb1d/01.img
/media/9edd991c-2497-4f92-aa86-bf6ccf9ddb1d/01.log
# current_pos  current_status
0x3B1840000     +
#      pos        size  status
0x00000000  0x3B1828000  +
0x3B1828000  0x00000200  -
0x3B1828200  0x00017E00  /

Why --no-split? Your image is far from complete as you have huge unsplit areas
as ddrescue hasn't been doing any splitting or retrying.

Try again with the options "-d -r 4" for direct mode with a few retries. Try
and stop your OS so much as breathing on the drive during the process.

Regards

Ian




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