Once again: cyrus backup

[Markus Heller]

Dear Colleagues,

I have found a documentation on the backup on cyrus imap, which says that I 
need to do this:

 tar -czf backup_spool.tar.gz /var/spool/imap
 tar -czf backup_lib.tar.gz /var/lib/imap
 
The first line is rather clear to me, but I cannot find the equivalent to the 
second line. What do I need to backup if I want to save my imap contents, 
install RC3 and restore the imap contents? 

Thanks in advance!

Markus