Jay Lessert <jayl AT accelerant DOT net> writes:

> As an aside on the speed issue... on estimate phase, 'ufsdump S' kicks
> GNU tar's butt.  It's not obvious to me exactly *why*; GNU tar is smart
> enough to know it's output file is /dev/null and not bother reading
> data blocks, but on my particular big file systems with lots of files,
> three estimate passes take literally hours longer with GNU tar compared
> to ufsdump.

GNU tar builds an index of all files in memory, and tries to keep that
index sorted (in order to optimize for hardlinked files?). This needs
a lot of CPU time. You might watch whether your tar process is
actually CPU-intensive.

        Sven