Rebuild the master device with the dataserver -w option: dataserver -w master Your dataserver command may include other options such as command line flags specifying the device path name, server name, interfaces file name, and so on. These options are listed in the RUN_servername file that normally starts this server. The -w master option causes Adaptive Server to search the device for database fragments belonging to the master database. After it finds these fragments, it writes a default master database into that space, then shuts down. Restart Adaptive Server with the RUN_servername file.