On Mon, Feb 9, 2015 at 5:51 PM, David Disseldorp <ddiss@xxxxxxx> wrote: > On Wed, 28 Jan 2015 19:22:03 +0100, David Disseldorp wrote: > >> > "A new File System Control (FSCTL) has been added to support the new >> > FSCTL_DUPLICATE_EXTENTS_TO_FILE operation in [MS-FSA]." >> >> I haven't played with it yet, but from the [MS-FCC] 20150119 preview >> doc it looks very similar to copy-chunk, with a few small differences: >> - It's only supported on ReFS, which may indicate that it's implemented >> using COW clones. > > The [MS-FSA] draft can be found at: > http://download.microsoft.com/download/C/6/C/C6C3C6F1-E84A-44EF-82A9-49BD3AAD8F58/Windows/%5BMS-FSA-Diff%5D.pdf > > It pretty much confirms that it's COW based: > "The purpose of this operation is to make it look like a copy of a > region from the source stream to the target stream has occurred when > in reality no data is actually copied. This operation modifies the > target stream’s extent list such that, the same clusters are pointed > to by both the source and target streams’ extent lists for the region > being copied." > > @Steve, it looks like the perfect candidate for cp --reflink mapping on > the client side. agreed. I will take a look against Windows 10 current beta to see if it accepts or rejects it. -- Thanks, Steve -- To unsubscribe from this list: send the line "unsubscribe linux-cifs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
