Patch to enable proper handling of Win32 //?/GLOBALROOT/device paths

Corinna Vinschen
Mon Oct 9 14:02:00 GMT 2006

On Oct  7 12:13, wrote:
> Thanks for the feedback. I've got a few supporting points though that
> may shed some more light on this.
> On Windows XP the only way to access VSS volumes is by specifying the
> temporary and dynamically generated GLOBALROOT path that the VSS COM API
> creates for you. You cannot persist and map them to a drive or share
> like you can on Server 2003 with the VSS API. 
> [...]
> However Cygwin already specifically allows access to the other form of
> GLOBALROOT access, //./GLOBALROOT, so you can already access most of the
> NT device namespace today. You can use tools like rsync with this form
> to access NT volumes right now. Unfortunately VSS volumes are not
> accessible under this form, which is why I added support for the
> //?/GLOBALROOT form. My patch is just to even out the GLOBALROOT access
> that already exists in Cygwin.
> With my patch you can use a tool like vshadow.exe to create a snapshot
> and then execute a tool like rsync to access them via the dynamic
> GLOBALROOT path, which vshadow provides via an environment variable.
> From my research into using tools like rsync on Win32, this is exactly
> what some people are trying to do as vshadow is known to be the tool
> available from MS for creating VSS snapshot volumes on Windows. Trying
> to use it with rsync is of course failing though. This patch address
> that.

I get the point.  Applied with minor modifications to comments and the
ChangeLog entry.


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

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