ntfsclone for cygwin 1.7 (issues pointing to shadow copies)

[Larry Hall (Cygwin)]

On 07/28/2009 05:27 AM, Corinna Vinschen wrote:
> On Jul 27 18:31, Larry Hall (Cygwin) wrote:
>> On 07/27/2009 05:48 PM, Rob Bosch wrote:
>>> The issue appears to be with ntfsclone in that it must point to
>>> something  in /proc/partitions. It will not work with any /cygdrive/X (used
>>> dosdev.c from Corinna and typical vshadow to expose as a drive with no luck). I found
>>> this out by commenting out the read-only check and rebuilding
>>> ntfsclone/ntfsinfo. The code apparently uses a win32_io.c file when building
>>> on cygwin. This file creates its own device mappings (e.g. /dev/hda1 instead
>>> of using the existing /dev/sda1). I guess there would be a way to modify it
>>> to use cygwin devices but I don't know how.
>>>
>>> If shadow copies could be presented as block devices to this library
>>> then  it would open up a lot of possibilities for creating block-level clones of
>>> partitions without having to boot to a live CD. I guess it is dd piped
>>> through gzip for now. It sure is a waste when you only have 50GB on a 500GB
>>> drive since dd processes the entire drive.
>>>
>>> Does anyone have anything else to add?  I'm guessing not...
>>
>> Not much in the way of specific help, no, but I can make two observations:
>>
>>    1. Using win32_io.c under Cygwin is almost certainly the wrong thing,
>>       since you'll then be using Win32isms in an environment built to expect
>>       POSIX mechanisms.
>>
>>    2. It looks like /proc/partitions isn't populated, so if /proc/partitions
>>       is the only way that ntfsclone expects to be able to find what it
>>       wants, then it will be disappointed until a patch is supplied to
>>       support this.
>
> /proc/partitions is populated, but only with actual disks.  The device
> mapping for disks is a mapping from the internal NT namespace objects
> \Device\HarddiskX\PartitionY to the POSIX-like /dev/sdXY.  Since shadow
> copies of a disk don't match this mapping, you're out of luck.  Maybe
> we can add a mapping in a later Cygwin release and I added it to my
> TODO list, but this is definitely no fodder for 1.7.1.

Ugh, my bad.  I forgot that '/proc/partitions' was a file and not a
directory.  It is populated for me as well.

-- 
Larry Hall                              http://www.rfk.com
RFK Partners, Inc.                      (508) 893-9779 - RFK Office
216 Dalton Rd.                          (508) 893-9889 - FAX
Holliston, MA 01746

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