Someone had posted about this and I deleted the email before I replied. 
I just wanted to follow up to what other folks had said.

Basically, it works well. The only advice that I would have is to create 
a snapshot of the filesystem and then run the rsync using the read-only 
copy as the source. That way, the filesystem is self-consistent and you 
will prevent the errors about missing files, etc.

With Solaris, look at the fsnap command. With Linux, utilize the 
snapshot feature of LVM. Other OSes have similar functionality. You will 
achive better and more consistent results with the snapshots than without.

Good luck!

-- 
Michael L. Barrow
michael at michaelbarrow dot name