This company has a solution maybe. Dunno much about how they do the live state.
netcat dd with some compression is simple enough.
You should be careful though. I don't know of a similar way in linux that ZFS or shadowcopy does it that actually picks an exact moment (live state). You should stop most applications to be sure you get the correct data.
May be on your system already.
Look for others but here is one link.
Other ideas are mondorescue and backula but plenty exist.
See also wayback versioning system.