On 05/25/16 02:29, Hugo Mills wrote: > On Wed, May 25, 2016 at 01:58:15AM -0700, H. Peter Anvin wrote: >> Hi, >> >> I'm looking at using a btrfs with snapshots to implement a generational >> backup capacity. However, doing it the naïve way would have the side >> effect that for a file that has been partially modified, after >> snapshotting the file would be written with *mostly* the same data. How >> does btrfs' COW algorithm deal with that? If necessary I might want to >> write some smarter user space utilities for this. > > Sounds like it might be a job for one of the dedup tools > (deupremove, bedup), or, if you're writing your own, the safe > deduplication ioctl which underlies those tools. > I guess I would prefer if data wasn't first duplicated and then deduplicated if possible. It sounds like I ought to write a "smart copy-overwrite" tool for this. -hpa -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
