Re: Shadowcopy volume block devices

[Corinna Vinschen <corinna-cygwin at cygwin dot com>]

On May 28 18:53, Micky wrote:
> >On Tue, May 28, 2013 at 6:35 PM, Corinna Vinschen wrote:
> >  If you knew that you could access
> > HarddiskVolumeShadowCopy using the POSIX path
> > why didn't you try to use the POSIX path as device name in a call to the
> > POSIX tool dd, rather than translating it into a Win32 path?  It's clearly
> > marked as block device in the directory listing:
> 
> Because if I do that, the dd goes into a loop dumping an endless amount of data.

That's not what you wrote in your OP.  You wrote "but it doesn't let you
access the volumes as block devices", which is pretty misleading as far
as bug reports go.

The endless loop problem accessing the device via /proc/sys/... should
be fixed in CVS now.

> When I tried c:\cygwin\dd.exe directly at the CMD with "\\.\" win32
> path, I got correct size of dump so that's why I knew something is up
> with the block devices presented inside Cygwin (at least for dd).

This has nothing to do with dd.  It just calls read(2) so the behaviour
is the same with any other application.  The difference is the handling
of DOS paths vs. the /proc/sys paths in the Cygwin DLL, the latter of
which had a bug.

I created a new developer snapshot.  Please give the 2012-05-28 Cygwin
DLL from http://cygwin.com/snapshots/ a try.  I also created a new 64
bit test release Cygwin package 1.7.19-8 with this patch included.


Thanks,
Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Maintainer                 cygwin AT cygwin DOT com
Red Hat

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