Re: [dm-devel] A simple, generic DM-API, for codecs/transcoders to use?

[Konrad Rzeszutek <konrad virtualiron com>]

On Wed, Mar 18, 2009 at 09:58:02AM +0100, Navid Zamani wrote:
> Hello DM mailing list.
> 
> I a have a simple question:
> Is there a way to use the device-mapper to hang an arbitrary program
> in-between a real block device, and the virtual device created by the
> device-mapper?
> Like with LUKS. Only that I do not want to compress or encrypt. I want
> to hang an error-correcting transcoder in between, so I can put ECC on
> any block device I want.
> The optimal thing would be a simple API, that is implemented in many
> languages. (Like FUSE is available in many languages.)
> Something like this would really be a powerful abstraction to have.
> 
> In case you are interested in the reasons: Modern consumer HDDs do not
> have any ECC, but they get less and less reliable. It went so far, that

I thought that the more recent patches by Oracle to support DIF/DIX (Data
Integrity Extensions):
http://oss.oracle.com/projects/data-integrity/dist/documentation/linux-hba.pdf

Are addressing this by adding a checksum for each block sector that is
checked by each device. So the firmware on the hard-drive, along with
the SAS controller would carry out the checksumming?