Both master KDC servers and slave KDC servers have copies of the KDC database stored locally. Restricting access to these servers so that the databases are secure is important to the overall security of the Kerberos installation.
Restrict physical access to the hardware that supports the KDC.
Make sure that the KDC server and its monitor are located in a secure facility. Regular users should not be able to access this server in any way.
Store KDC database backups on local disks or on the KDC slaves.
Make tape backups of your KDC only if the tapes are stored securely. Follow the same practice for copies of keytab files.
The recommended practice is to store these files on a local file system that is not shared with other systems. The storage file system can be on either the master KDC server or any of the slave KDCs.