Checking RAC status

1. Cluster status
 $crs_stat -t

$crsctl check crs

2. Check status of individual nodes and all the necessary applications

$srvctl status nodeapps -n host<n>

3.   check the status of the ASM on both nodes

$srvctl status asm -n host<n>

4. Check database status

$srvctl status database -d <dbname> 

5.Querying the RAC

SQL> select instance_name, host_name, archiver, thread#, status
  2  from gv$instance
  3  /

SQL> select file_name, bytes/1024/1024
  2  from dba_data_files
  3  /

SQL> select group#, type, member, is_recovery_dest_file
  2  from v$logfile
  3  order by group#
  4  /

SQL> select group_number, name,allocation_unit_size alloc_unit_size,state,type,total_mb,usable_file_mb
from v$asm_diskgroup; 

SQL> select name, path, header_status, total_mb free_mb, trunc(bytes_read/1024/1024) read_mb, trunc(bytes_written/1024/1024) write_mb
from v$asm_disk;

SQL> select name from v$datafile
  2  union
  3  select name from v$controlfile
  4  union
  5  select name from v$tempfile
  6  union
  7  select member from v$logfile
  8  /

SQL> select tablespace_name, file_name
  2  from dba_data_files
  3  union
  4  select tablespace_name, file_name
  5  from dba_temp_files
  6  /

SQL> select group_number, file_number, bytes/1024/1024/1024 GB, type, striped, modification_date
  2   from v$asm_file
  3  where TYPE != 'ARCHIVELOG'
  4  / 

SQL> select group_number, file_number, compound_index, incarnation, block_size, bytes/1024/1024/1024 GB, type, striped,
  2  creation_date, modification_date
  3  from v$asm_file
  4  where TYPE != 'ARCHIVELOG'
  5  /