Linux – What happens when you rsync without a destination

The -C option for rsync may be what you want.

Don't let the short description in the man page fool you though. It would seem like the option only applies to CVS, but depending on your rsync version it will skip the files of almost every common version control system in existence.

# rsync version: 3.0.7

-C, --cvs-exclude           auto-ignore files in the same way CVS does

...

          The exclude list is initialized to exclude the  following  items
          (these  initial  items are marked as perishable — see the FILTER
          RULES section):

                 RCS  SCCS  CVS  CVS.adm   RCSLOG   cvslog.*   tags   TAGS
                 .make.state  .nse_depinfo *~ #* .#* ,* _$* *$ *.old *.bak
                 *.BAK *.orig *.rej .del-* *.a *.olb *.o *.obj *.so  *.exe
                 *.Z *.elc *.ln core .svn/ .git/ .bzr/

          then,  files  listed in a $HOME/.cvsignore are added to the list
          and any files listed in the CVSIGNORE environment variable  (all
          cvsignore names are delimited by whitespace).

The short answer is yes, you can use lftp.

But since it looks like you are backing up a running system, which will include changed (log-)files, you are IMHO better of sticking with rsync, which handles changed files by sending (compressed) deltas, not by uploading complete new files.

You can use a script that repeatedly runs rsync. The first rsync will take long time (determined by the network speed and size of the source), the second and following runs much less time as only changed, added information is being sent. lftp will unlikely be significantly faster on the first "transfer" and slower on the following ones.

You might also want to look at rdiff-backup, which usses the rsync protocol underneath, but also can preserve deltas to roll-back to previous states (at the cost of extra disc space on the destination host).