Excerpts from Erik Logtenberg's message of 2010-12-15 14:14:15 -0500: > Chris, thank you very much for your explanation. Indeed this clears > things up a bit. > > >>> Caveat: Defragmenting a file which has a COW copy (either a snapshot > >>> copy or one made with bcp or cp --reflinks) will produce two unrelated > >>> files. If you defragment a subvolume that has a snapshot, you will > >>> roughly double the disk usage, as the snapshot files are no longer COW > >>> images of the originals. > >> > >> [2] https://btrfs.wiki.kernel.org/index.php/Problem_FAQ > >> > >> >From what I've heard on IRC this is still the case in current versions, > >> but the Btrfs(command) documentation contains no mention of this. > > > > This is still true. > > Is there a decent way to have btrfs compress already existing files > (that were written before compression was enabled) without hurting any > of the internal structures such as snapshots? I'm afraid not yet. There is code for this in the btrfs balance routines, but we haven't yet adapted it to the defragment command. -chris -- 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
