Oracle internals, debugging and undocumented features
One of the prerequisites to successfully install Oracle version 11.2 is to set Network Time Protocol ( NTP )
( file /etc/sysconfig/ntpd )
with -x flag which prevents time from adjusting backward.
This comes very crucial in debugging Oracle Clusterware.NTP will synchronize clocks among all nodes which will make correct analysis of trace files based on time stamps .
Oracle is providing diagnostic collection script diagcollection.pl to collect important log files.
Script is located under $<GRID_HOME>/bin/ e.g. /u01/app/11.2.0/grid/bin
It will generate four tar.gz files in local directory which will have following information:
traces,logs and cores for CRS home
ocrcheck , ocrdump
CRS core files
After you are done you can clean them with same script.Just run diagcollection.pl -clean option.
Script must be run as root .