Using storage offloading capabilities

[Federico Simoncelli]

Hi everyone,
 I am evaluating the possibility to add some storage offloading
capabilities to existing utilities.
For example I'd be interested in leveraging WRITE SAME and EXTENDED
COPY scsi commands to initialize and copy data on iscsi/fcp devices.

It seems that both commands could be easily added to dd, WRITE SAME
for example could be implemented as the "sparse" conv (detecting
zeroes in the input stream) and EXTENDED COPY can be attempted when
input and output devices are sg devices.

There's also a more ambitious goal of adding support for the device
mapper (e.g. lvm logical volumes) reading the dm table and using the
correct offsets to offload the initialization and the copy to the
storage. I already did a quite extensive analysis on how to actually
implement that but I don't want to mix too many subjects at once.

As initial step I'd like to understand if there's some interest in
adding offloading support to dd.

Thanks,
-- 
Federico