What is being collected and why?
Oracle Support strongly recommends using TFA Collector for collecting data. TFA Collector collects only relevant information based on the time of the event, so the size of collected data will be much smaller. TFA Collector collects all CRS log files, ASM trace files, database trace files, OSWatcher output, and CHM (Cluster Health Monitor) output.
TFA Collector is installed in the Grid Infrastructure home and comes with 11.2.0.4 Grid Infrastructure and higher (excluding 12.1.0.1) - on UNIX platforms and with Grid Infrastructure 12.2.0.1 and higher - on Windows platforms.
Reference: Document 1513912.1 TFA Collector - Tool for Enhanced Diagnostic Gathering
Safe Harbor Statement: Oracle will use this information to help diagnose the cause of the issue. In many cases this set of information will be sufficient for diagnosis - in some cases additional specific diagnostic data may be required at a later stage.