What is the PID.NBF file?
The PID.NBF file is the Process ID table of all Notes/Domino processes. For the lifetime of a Notes client/server, each process start or shutdown causes the process ID (PID) to be added to or removed from the PID.NBF.
In a Win32 environment, NSD uses the pid.nbf to determine, in case of a crash, if the failing process is a Notes/Domino process. The PID.NBF file is also used by Domino in a partitioned server environment. The file allows the processes associated with each partitioned server to be identified.
The PID.NBF is located in the Domino\Data directory. The PID.NBF file can be renamed or deleted. The file is recreated the next time the Domino server is restarted. If the PID.NBF file is deleted while the Domino server is running, NSD will be unable to determine the Notes processes to attach to until the server is restarted (when the new PID.NBF is created).