[csw-users] Why this strange behavior coping /opt/csw

[Harry Putnam]

Running Openindiana (solaris branch) and using some csw tools too.

csw stuff is installed at /opt/csw.  Since my root pool space is
shrinking I thought I might move all of /opt off on a different zpool
on a different disc.  Then just put a symlink in place at /opt.

I decided to do it with rsync and after rsyncing everything to /t1/opt
 (rsync -avv /opt/ /t1/opt/ )

But when I check the result with du I find a huge difference in size.

the original /opt shows 355 MB but the copied opt shows only 173 MB

I thing tried with copy  using gnu copy  and did 'cp -a' /opt/t1/

Again it comes up with the big difference in size..

Any ideas what could explain that?