I've been looking for this for sometime to no avail. Is it possible to backup a btrfs partition verbatim (including all the shared structures which save space by marking snapshot trees as COW) to another one? For instance, I'd like to backup my root partition which has couple of btrfs subvolumes (snapshots of the / itself).
The only way I can think is to use a block copying tool like dd but that is inefficient as my partition is only 20% full and I intend to back it up regularly. I already backup everything incrementally using rsync, so this is not a workaround for another problem. I simply need a bit for bit clone of my btrfs partition without having to use a tool such as dd.
I know ext3, for instance, provides a dump and restore utility. That is the kind of thing I'm looking for.
Here is a update to clarify the fact that I want to be able to access the files on the backup storage the same way I can on the live disk (ie I do not want to store dump files on the backup storage).
Thanks in advance