bi monthly based Mail/News backup scheme

[reader at newsguy.com]

Matt McCutchen <matt at mattmccutchen.net> writes:

[...]

>> 
>> The end result would be (after 12 months) new top level directory started
>> every 4th month and no overlap where the changeover occurs.
>> 
>>     jan-feb-mar-apr/  may-jun-jul-aug/  sep-oct-nov-dec/
>
> I think these names are unwieldy.  You might consider a naming scheme
> like 2008T1, 2008T2, 2008T3 (T for third, like Q for quarter)
> instead.

He He... yup they are... but used for clarity in this post.  I do like
your scheme though.  However what I really use is almost too
embarrassing to post:

   010107-043007/ 050107-083107/ 090107-123107/

I'm pretty sure I would still end up mentally scrolling the mnths to
know what was under there with your scheme.

I've grown accustomed to glancing at the above kind of date format from
using it to keep versions of scripts or other file naming chores where
you need to know the vintage quickly.  Although a little different in
those cases because I add the time as well:
  
    file-041406_130821  with a little function I've used for yrs:
  
  date_f () {
    date +"%m%d%y_$H%M%S"
  }
In fact I haven't really ever got the backup scheme working like I
wanted so those names have never really come into use for that.  But
now with the nifty switch... I can get this going.

>> Its a given that rsync has a wonderfully flexible set of flags and
>> switches. Still, near as I can tell what I described is not possible,
>> using only rsync switches.
>
> There's a switch just for you: --compare-dest.  Copy to the new
> destination and specify the old destination as a --compare-dest
> directory to have rsync skip copying source files that appear
> identically in the old destination.

Nice.... I'm sorry for the line noise... somehow it wasn't clear to me
in the manpage what that really did.