Why does one of there work and the other doesn't

[Ian Kettleborough]

I was planning to use rsync to backup to a second drive, but I ran out of
swap space. No problem, I will let rsync do it a few directories at a time
overnight when the computer usually sits idle except for incomming email.

I have 2 question:

1. How much memory does each file to be copied need. Obvisiouly I have too many
files.

2. Why does this command work:

        rsync -ax /usr/xx /backup/usr/


  when:

        rsync -ax /usr/xx/ /backup/usr/ 

        refuses to create the directory xx in /backup/usr and copies
        the contents of the directory to /backup


Happens on both 2.4.7Pre4 and 2.5.0 just released.

Thanks
Ian