Subject to my research, looks like by using "stsadm" utility to backup Sharepoint 2.0 is not enough if the Sharepoint site contains sub-site below the Top-site. Because in my test, once it is restored, I cannot see the sub-sites, only one sub-site can be restored. Thereofre I found that I might able to use "smigrate" utility. However; I have some unconfirmed question.
1. If using smigrate utility to backup, can I just backup one sub-site, or once it is issued; all sub-sites and the top site will be backed up.
smigrate -w http://companyweb
2. My drive to keep the current Sharepoint database has 56GB space left and my sharepoint database is 31GB large, is it good enough if the "smigrate" utility would backup the entire site.