Re: [hobocopy] Comparison with vscopy?
Craig Andera
some time looking at it, and at a high level, it looks like the two
tools are pretty similar. Vector also makes his source available,
although it looks like he wrote his in assembler! And yes, ShadowSpawn
has versions available for 32-bit XP and for 32- or 64-bit W2K3,
Vista, W2K8, and Windows 7.
From a usage perspective, there are two major differences that we
could see. First, ShadowSpawn lets you specify arguments, and I don’t
think vscopy does. That is, if you wanted to run something like
“robocopy Q:\path\to\thingy.txt C:\destination\path” as a command,
with vscopy you’d have to create a .bat file with that command in it.
With ShadowSpawn, you’d just include the arguments on the command
line.
A second, more subtle difference is that ShadowSpawn more fully
exercises the Volume Shadow Service (VSS) API to create
fully-consistent copies. What this means is that ShadowSpawn gives
software like SQL Server a chance to flush its state to disk before
the shadow copy takes place. With vscopy, you get a snapshot of
whatever happened to be on the disk at the time. This is called a
“crash consistent” copy.
Or at least, we think so. The truth is that the VSS API is pretty
impenetrable, and it’s entirely possible that it doesn’t work the way
we think it does.
I’ve cc’d the ShadowSpawn mailing list. Questions about ShadowSpawn
are best sent there. Thanks!
On Thu, Aug 25, 2011 at 7:23 PM, ajl <achim....@gmail.com> wrote:
> Hello list:
>
> I just found the news about ShadowSpawn, and was wondering how it
> compares with vscopy [1, 2] from a user's point of view?
>
> From a cursory glance, the use cases and the command line arguments
> seem pretty similar:
>
> shadowspawn [ /verbosity=LEVEL ] <src> <drive:> <command>
> [ <arg> ... ]
> vscopy <volume_letter> <assigned_letter> <file_to_execute>
>
> Is ShadowSpan also compatible with XP, 2k3/Vista and W7?
>
> I do appreciate the source code availability and licensing of
> ShadowSpawn, of course.
>
> Best regards, Achim
>
> [1] <http://www.masm32.com/board/index.php?topic=13103.0>
> [2] <http://www.vortex.masmcode.com/>