You can't really calculate catalog size as a function of data backed
up.  It's dependent on number of files, length of the path names (and
marginally other metadata), and number of copies kept.  You may have
found that 3% works out in your environment, but if for example you
cut your retention period in half, it'd be more like 1.5% (or you
could double it and go for 6).  Likewise, shops with large amounts of
their data stored in databases (small number of files or raw devices
relative to the amount of data) will have a much smaller percentage
than shops with lots of small files (web servers maybe).

Yes, some (optional) changes are coming.  The general structure will
remain the same, but some redundant information in the "files files"
(the vast majority of space usage) can be removed by using a new
format.  This should reduce the catalog size, and improve search
performance.  More details will be available as we get closer to
implementation.

Jeff Kennedy writes:
> Larry,
> 
> Does Veritas have any plans to make the catalogue more efficient?  I
> have figured that the catalogue takes about 3% of the total data backed
> up, which can be huge in current environments and it will do nothing but
> get bigger.  I realize that compression is an option but that can lead
> to issues in time to restore, which is why we backup in the first
> place.....
> 
> Thanks.
> 
> -- 
> =====================
> Jeff Kennedy
> Unix Administrator
> AMCC
> jlkennedy AT amcc DOT com

-- 
Larry Kingery 
            Don't look back, they might be gaining on you.