Re: [Bug-ddrescue] How to restore just a single parti tion of a multi-partition image file?

[Shahrukh Merchant]

Thanks David, your response, as well as Timothy's response to my 
question as to why use the NTFS tools for a partition-based copy, allude 
to the difference between a partition-based clone (sector by sector 
copy) vs. a file-system based clone (file by file copy).

For backup recovery purposes, I'm very skeptical of file-based "clones" 
because any number of utilities have subtle problems in copying (e.g., 
files with super-restricted permissions such as ownership by "Trusted 
Installer," very long full pathnames, odd characters in the file names, 
etc.). I have been bitten by this more than once. I stopped using Norton 
Ghost about 10 years ago just because of this: I couldn't open their 
proprietary (yet another problem) backup file format in their restore 
utility because ONE file had a filename that exceeded some length. I 
moved on to Image for

On 2019-01-24 4:54 AM, David Morrison wrote:
> I think you might be making this too hard, but I am writing this from a 
> Mac user perspective where if it was a Mac disk, this is what I would 
> do. I imagine similar tools are available for Windows.
>
> The first thing you would do is to mount the disk image of the failed 
> disk so it is visible as a file system. This would typically mount the 
> partitions on that disk image individually. Preferably you would mount 
> them read only, and there are ways to do that through the command line 
> on Mac or a utility called Disk Arbitrator.
>
> Having got the partition I wanted accessible from the file system, I 
> would then Restore it to the correct partition on the new disk using 
> Disk Utility. (Clonezilla should be able to do this too.)
>
> The advantage of this technique over ddrescue is that you are not 
> copying block-by-block to the new partition, complete with any weirdness 
> that contains. Instead you are copying as files, which will copy to the 
> full new partition rather than just the first 200GB that ddrescue will 
> copy to. It would also set up boot blocks, etc as they need to be to be 
> bootable.
>
> This should also clear up any damage to the filesystem, if it can repair 
> it. But ofc if the C drive is very damaged as you suggest, then you have 
> to wonder whether it will be capable of doing anything afterwards.
>
> Cheers
>
> David