HAMMER history friendly backup tool

[Predrag Punosevac]

It looks increasingly unlikely that I will get any suggestions to the
original question so I am just going to post my own "solution" to the
original problem.

Namely I was looking for a backup utility which will play well with
HAMMER history. I should have started by searching this list for my own
posts. Namely in January of 2013 I asked somewhat related question
"Unison and HAMMER history"

https://marc.info/?l=dragonfly-users&m=135857302406777&w=2

I remember that after Unison sync the file history was lost. What I
didn't remember until today was that Peeter noticed that the same was
true with rsync 

https://marc.info/?l=dragonfly-users&m=135885584004499&w=2

which indeed shares the main algorithm with Unison.  He also noticed
that using scp or even a cp over NFS (my observation which is fully
tested) will play well with HAMMER history. So long story short it would
be fairly easily to cook up such a backup tool which will traverse the
on my home directory (running OpenBSD) and just cp the files which have
changed since the last run. I also tested rdiff-backup if anybody cares
and the result is the same as with rsync and unison.

Personally I decided to run HAMMER snapshot as a cron job after rsync
and in that way preserve the older version of files. 

By the way DragonFly NFS server is playing very nice with OpenBSD nfs
client and I am tempted to move my home directory to DF NAS. History
works like a charm.

Predrag