Hi, On Wed, Sep 23, 2015 at 09:41:21AM +0100, Filipe David Manana wrote: > On Tue, Sep 22, 2015 at 9:04 PM, Hugo Mills <hugo@xxxxxxxxxxxxx> wrote: > > On Tue, Sep 22, 2015 at 09:52:19PM +0200, carlo von lynX wrote: > >> Hello, it's me again. This time I searched the web to make sure > >> I'm not making another beginner's mistake. I'm still not on the > >> list, so please keep me in cc: on replies. > >> > >> I have optimized a btrfs subvolume with a script* that reflinks > >> all files with identical contents, then I did a read-only snap > >> and fed it to send/receive. The bad news: on the receiving > >> side the same snapshot grew from 5.5G to 7.1G. > > So that's likely because you have files with holes. Right now when a > hole exists in a file the send stream will contain an instruction to > write zeroes into the file instead of a punch hole instruction. So > imagine a file with a 1Gb hole, the send stream makes the receiver > write 1Gb of zeroes, wasting a lot of space (and time). > > There's an over an year old patchset to add hole punching support to > the send stream and a few other features, but it was never picked by > Josef at the time (when he was maintaining the integration branch) nor > Chris. > Can you please point to the latest version of the hole punching patchset? Thanks, -- Pasi -- 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
