As with any valuable data, you should make sure that your virtual search server files are backed up. At minimum, you should back up your index files, which by default are stored in volume:\qfsearch\Sites\sitename\indexes on NetWare and in /var/lib/qfsearch/docs/index.html on Linux.
If you have customized templates, you might also want to back them up. By default, they are stored in volume:\qfsearch\Templates on NetWare and in /var/lib/qfsearch/Templates on Linux.