Hugo Mills <hugo <at> carfax.org.uk> writes: > > On Mon, Apr 20, 2015 at 02:15:47PM +0000, sri wrote: > > Hi, > > > > I have a subvolume with only one file (file.txt) with 5Mb size. > > under /btrfs/subvol1/ > > 1) > > I have created 1st snapshot /btrfs/snap1_subvol1. Then I ran "btrfs > > send" and given -f out1.img > > > > size of out1.img is 5Mb. > > > > 2) > > Next, I have appended 1Mb data to file.txt > > > > And again created snapshot /btrfs/snap2_subvol2. And rand "btrfs send" > > out put to file out2.img > > > > 3) > > After that I ran "btrfs send -p /btrfs/snap1_subvol1 > > /btrfs/snap2_subvol1 -f outwith_poption.img. > > > > Beween out1.img and out2.img there is difference of 1Mb > > > > I would like to know what is the difference between out2.img and > > outwith_poption.img ? > > > > When I do btrfs send to a file, is there a way to send only changes to > > new file i.e. for step 2 and step 1, out2.img is 6Mb and out1.img is > > 5Mb. > > Basically, do exactly what you did with step 3. -p is the base > subvolume, and only the differences from that are sent. > > Hugo. > > > can I get difference if the file and use it as input to btrfs receive > > option if I want to recover incremental recover i.e out1.img + 1Mb ?? > > > > Here with my steps I can give only out2.img which is of 6Mb or out1.img > > which is of 5Mb. > > So for incremetal backup, it consumes total of 11Mb. > > I want a way to reduce it to total of 6Mb but there should a way to > > recover from fist snapshot dump and second snapshot dump as well. > Hi Hugo, Could you please elaborate more on your point. What I am looking is a way to just to collect differences of previous send dump and further send dumps which are from incrementail snapshots. btrfs send on first snapshot is 5Mb (say). the Further sends on snapshots should be able to collect only difference between already collected dump of 5Mb to the latest and go further. first send dump 5Mb dump1.img (size 5mb) sencod send dump 1Mb dump_incr1.img (size should be 1Mb but it is 6Mb) third send dump 3Mb dump_incr2.img ( size should be 2Mb but it is 7Mb) And looking for a way of giving dump_incr2.img to btrfs receive (also makre sure other file dump1.img and dump_incr2.img) are available, and recreate subvolume on destination btrfs fs. -- 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
