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 saw random corruption without SMART telling me of any errors. (Of course I eliminated the software as a cause.) RAID, backups and all that stuff, does not help. Because this is a consumer case, and frankly, I do not have the money for a RAID. Backups do not help, because you back up your corrupt files with everything else, and only notice it, when it’s too late. So I decided to put my whole archive on a partititon with software-based ECC. And because I could not find something that resembled this, I chose to implement it myself. I will program it in Haskell, and use cross-interleaved Reed-Solomon codes (much like those on CDs) as a ECC. Is is a must-have to 1. fix corruption on read (and re-write the fixed data), 2. report any tiny problem to the user (log, mail, console message. all at once if possible), and 3. protect the whole partition (else I would have used FUSE). I bet there are more people out there who could use something like that. Most certainly certain government agencies or scientists. I wonder, what you have to say about this. Is there something like this out there? Is there a better way? How would I implement it with the device-mapper. Navid -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
