Source:  AIOCON

Explanation:  You selected the Disk File option while starting a port trace, but the system was unable to create the specified file. There is not enough disk space, the volume is not mounted, or an invalid filename was specified.

Action:  Add memory to the server or increase the available server memory using one of the methods described in Resolving Memory Problems. Verify that the volume is mounted. Verify that a valid filename was specified.