- If the instance is hanging and you can't log in to any instance, please do one of these 2 options instead:
1) Use "sqlplus -prelim / as sysdba" to get into sqlplus on one instance, and run the oradebug statements 2-3 times - 1 minute apart:
SQL> oradebug setmypid
SQL> oradebug unlimit
SQL> oradebug -g all hanganalyze 3
SQL> oradebug -g all dump systemstate 267
This only needs to be done on one instance; the "-g all" will kick off collection on all the other instances.
2) Capture systemstate dumps from each node with an OS debugger (gdb):-or-
ps -ef |grep diag
gdb $ORACLE_HOME/bin/oracle
print ksudss(266)This must be done on each node.