bind 9.9.1-P1 renamed some slaves zone files. How to prevent it to do so?

[Kovács Albert]

Hello,

I have bind 9.9.1-P1 as a slave dns. I noticed that it couldn't access some zones from the master server, and it renamed some zone files to "db-xxxxxxxx"

The following message was logged:

"zone foo.bar/IN: unable to load from 'foo.bar.zone'; renaming file to 'db-L3yXPcbQ' for failure analysis and retransferring."

My question is how to make the slave server not to touch the zone file (and keep serving the zone) if the master dns server weren't available?

Alberto