Oracle RAC SRVCTL and CRSCTL tools
Check RAC and Cluster health
Using SQLPLUS and find the RAC Instance status -
sql>select instance_name, host_name, archiver, thread#, status from gv$instance;
sql>show sga
sql>select file_name, bytes/1024/1024 from dba_data_files;
sql>show parameter undo
sql>select group#, type, member, is_recovery_dest_file from v$logfile order by group#;
sql> select distinct thread#,group# from gv$log;
sql> select name from v$datafile