Starting with Oracle Clusterware 12c release 1 (12.1.0.2), diagnostic data files written by Oracle Clusterware programs are known as trace files and have a .trc file extension, and appear together in the trace subdirectory of the ADR home. The naming convention for these files generally uses the executable program name as the file name, possibly augmented with other data depending on the type of program.
Trace files written by Oracle Clusterware command-line programs incorporate the Operating System process ID (PID) in the trace file name to distinguish data from multiple invocations of the same command program. For example, trace data written by CRSCTL uses this name structure: crsctl_PID.trc. In this example, PID is the operating system process ID displayed as decimal digits.
Trace files written by Oracle Clusterware daemon programs do not include a PID in the file name, and they also are subject to a file rotation mechanism that affects naming. Rotation means that when the current daemon trace file reaches a certain size, the file is closed, renamed, and a new trace file is opened. This occurs a fixed number of times, and then the oldest trace file from the daemon is discarded, keeping the rotation set at a fixed size.
Most Oracle Clusterware daemons use a file size limit of 10 MB and a rotation set size of 10 files, thus maintaining a total of 100 MB of trace data. The current trace file for a given daemon simply uses the program name as the file name; older files in the rotation append a number to the file name. For example, the trace file currently being written by the Oracle High Availability Services daemon (OHASD) is named ohasd.trc; the most recently rotated-out trace file is named ohasd_n.trc, where n is an ever-increasing decimal integer. The file with the highest n is actually the most recently archived trace, and the file with the lowest n is the oldest.
Oracle Clusterware agents are daemon programs whose trace files are subject to special naming conventions that indicate the origin of the agent (whether it was spawned by the OHASD or the Cluster Ready Services daemon (CRSD)) and the Operating System user name with which the agent runs. Thus, the name structure for agents is:
origin_executable_user_name
Note:
The first two underscores (_) in the name structure are literal and are included in the trace file name. The underscore in user_name is not part of the file naming convention.
In the previous example, origin is either ohasd or crsd, executable is the executable program name, and user_name is the operating system user name. In addition, because they are daemons, agent trace files are subject to the rotation mechanism previously described, so files with an additional _n suffix are present after rotation occurs.