Hello Andrew,
Dryrun won't be able to detect missing structural entries: that requires a database. Even an internal list of DNs is not enough, as the actual entries have to be available in order to check things like schema and content rules.
To be a valid test you really have to import the data into a server with configuration identical to the production server. If that would take too long then a reasonable compromise might be to import to a server set up to write data as fast as possible. You could reasonably turn off all database-safety functions to do that, or put the database on a ramdisk. Even if you use hdb on the production servers you might consider trying mdb for the backup tests.
Thanks for enlighten me. I've a separate backup server (read only slave), where I can do this. So I'll try to get money from the FC for more RAM to make the test in a ramdisk ^^
kindly regards
Meike