Hi Kent, nice to have you in this discussion! > > I understand that the actual implementation is easier and, > > maybe, simpler, since a completely new device is added, > > which will have the new caching "features", while the > > old one (backing device) is just a further layer. > > This is similar to LVM over md over /dev/sdX. > > The reason for getting rid of transparent caching didn't have anything > to do with ease of implementation: the real reason is that safely doing > persistent caching (and writeback!) is impossible with transparent > caching. Well, it seems to me "impossible" is a big word... I could image is more "invasive". > Adding back a mode that caches a device without a bcache superblock but > without the cache being persistent isn't out of the question, but it I miss the point, the superblock can be stored in the caching device, instead of the backing and the actual device *could* stay the same. The kernel would have to discover first the caching, later the backing and then put things together. So, the cache will be persistent, or? As I wrote above, I see this more complex than adding a further layer, likely I would do the same. > wouldn't be terribly useful to us so it's not at all a priority for me. > If someone else wrote the code I'd take patches, though. No time for that, unfortunately. I take the opportunity to congratulate personally to you for this project, well done! bye, -- piergiorgio -- To unsubscribe from this list: send the line "unsubscribe linux-bcache" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
