Check the status of the ASM instance in RAC

[oracle@oel6-112-rac1 Desktop]$ srvctl status asm ASM is running on oel6-112-rac2,oel6-112-rac1 

Command to check whether Oracle Flex ASM is enabled or not

[oracle@oel6-112-rac1 Desktop]$ asmcmd ASMCMD> showclustermode  ASM cluster : Flex mode enabled ASMCMD> showclusterstate Normal

Command to change the cardinality of the ASM

[oracle@oel6-112-rac1 Desktop]$ srvctl status asm -detail ASM is running on oel6-112-rac2,oel6-112-rac1 ASM is enabled. 
[oracle@oel6-112-rac1 Desktop]$ srvctl config asm -detail ASM home: /u01/app/12.1.0/grid Password file: +DATA/orapwASM ASM listener: LISTENER ASM is enabled. ASM instance count: 3 Cluster ASM listener: ASMNET1LSNR_ASM

Command to check whether Oracle Flex ASM is enabled or not

[oracle@oel6-112-rac2 Desktop]$ asmcmd ASMCMD> showclustermode ASM cluster : Flex mode enabled ASMCMD> showclusterstate Normal ASMCMD> exit

How to change the cardinality of the ASM

[oracle@oel6-112-rac2 Desktop]$ srvctl config  asm -detail ASM home: /u01/app/12.1.0/grid Password file: +DATA/orapwASM ASM listener: LISTENER ASM is enabled. ASM instance count: 3 Cluster ASM listener: ASMNET1LSNR_ASM

Bringing Down the ASM instance in RAC Database instance1

[oracle@oel6-112-rac1 Desktop]$ srvctl stop asm -node oel6-112-rac1 -stopoption abort -force

Check the status of ASM instance in RAC Database instance1

[oracle@oel6-112-rac1 Desktop]$ srvctl status asm PRCR-1070 : Failed to check if resource ora.asm is registered Cannot communicate with crsd

Checking the status of cluster services in RAC Database instance1

[oracle@oel6-112-rac1 Desktop]$ crsctl check cluster CRS-4535: Cannot communicate with Cluster Ready Services CRS-4529: Cluster Synchronization Services is online CRS-4533: Event Manager is online 

Checking the status of ASM & RAC Database in instance1

[oracle@oel6-112-rac1 Desktop]$ ps -ef | grep pmon oracle    3813     1  0 17:40 ?        00:00:00 mdb_pmon_-MGMTDB oracle    5806     1  0 17:42 ?        00:00:00 ora_pmon_orcl1 oracle    6193     1  0 17:42 ?        00:00:00 apx_pmon_+APX1

Note: Here a database instance is associated with the specific ASM instance running in the specific node. If for some reason the ASM instance was unable to be brought up or the service goes down, the database instance can still be brought up as the database instance will look for an ASM instance running on the same cluster.

Check the status of RAC Database instance running without ASM instance in RAC database instance1

[oracle@oel6-112-rac1 Desktop]$ . oraenv ORACLE_SID = [orcl1] ? orcl1 ORACLE_HOME = [/home/oracle] ? /u01/app/oracle/product/12.1.0/db_1 The Oracle base remains unchanged with value /u01/app/oracle

Log into Database instance from RAC database instance1

[oracle@oel6-112-rac1 Desktop]$ sqlplus /nolog SQL*Plus: Release 12.1.0.1.0 Production on Wed Sep 25 18:24:36 2013 Copyright (c) 1982, 2013, Oracle.  All rights reserved.  SQL> connect sys/oracle@orcl as sysdba Connected.  SQL> select instance_name,instance_number from gv$instance; INSTANCE_NAME           INSTANCE_NUMBER ------------------------------------------- orcl2                         2 orcl1                         1 
SQL> select instance_name,instance_number from v$instance; INSTANCE_NAME INSTANCE_NUMBER ------------------------------------------- orcl2 2 SQL> connect sys/oracle@orcl as sysdba Connected.

Connecting to ASM instance of RAC Database instance2 from RAC Database instance1

[oracle@oel6-112-rac1 Desktop]$ . oraenv ORACLE_SID = [orcl1] ? +ASM2 ORACLE_HOME = [/home/oracle] ? /u01/app/12.1.0/grid The Oracle base remains unchanged with value /u01/app/oracle  [oracle@oel6-112-rac1 Desktop]$ asmcmd --privilege sysasm --inst +ASM2  ASMCMD> lsdg State    Type    Rebal  Sector  Block       AU  Total_MB  Free_MB  Req_mir_free_MB  Usable_file_MB  Offline_disks  Voting_files  Name MOUNTED  EXTERN  N         512   4096  1048576     15342     4782                0            4782              0             Y  DATA/ ASMCMD> 

check how many ASM instances have been specified for use

# srvctl config asm | grep -i count ASM instance count: 2

change the configuration to have 3 ASM instances active

# srvctl modify asm -count 3

# srvctl status asm -detail