Vladislav Bolkhovitin wrote: > > I would also suggest one more feature: support for block level > de-duplication. I mean: > > 1. Ability for Btrfs to have blocks in several files to point to the > same block on disk > > 2. Support for new syscall or IOCTL to de-duplicate as a single > transaction two or more blocks on disk, i.e. link them to one of them > and free others > > 3. De-de-duplicate blocks on disk, i.e. copy them on write > > I suppose that de-duplication itself would be done by some user space > process that would scan files, determine blocks with the same data and > then de-duplicate them by using syscall or IOCTL (2). > > That would be very usable feature, which in most cases would allow to > shrink occupied disk space on 50-90%. Have you references for this number? In my experience one gets a lot of benefit from the much simpler process of "de-duplication" of files. Note a checksum stored in file metadata, that is automatically invalidated on write would speed up user space file de duplification, and rsync, etc.... Pádraig. - To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
