Questions about SPFILE in ASM 11G
I did some tests on Oracle 11G ASM and questions arose.
Look..
I deleted my SPFILE, and start the ASM.
echo $ORACLE_HOME
/u01/app/11.2.0/grid_crs
export ORACLE_SID=+ASM1
sqlplus / as sysasm
Connected to an idle instance.
SQL> startup
ORA-00099: warning: no parameter file specified for ASM instance
ASM instance started
Total System Global Area 283930624 bytes
Fixed Size 2212656 bytes
Variable Size 256552144 bytes
ASM Cache 25165824 bytes
ORA-15110: no diskgroups mounted
Oracle instance started a dummy ..
SQL> show parameter dummy
dummyinstance boolean TRUE
Now I will create a PFILE to start the ASM.
vi /home/oracle/asm_init.ora
*.cluster_database_instances=2
ASM1.instance_name='ASM1'
ASM1.instance_name='ASM2'
*.instance_type=ASM
*.asm_diskstring='/dev/oracleasm/disks/*'
*.diagnostic_dest='/u01/app/oracle'
*.asm_diskgroups='DATA'
*.asm_power_limit=1
*.large_pool_size=12M
*.remote_login_passwordfile='EXCLUSIVE'
Now i will start instance with new PFILE.
SQL> startup pfile=asm_init.ora
ASM instance started
Total System Global Area 283930624 bytes
Fixed Size 2212656 bytes
Variable Size 256552144 bytes
ASM Cache 25165824 bytes
ASM diskgroups mounted
ASM diskgroups volume enabled
Now I will create the SPFILE from PFILE.
SQL> create spfile='+DATA' from pfile='/home/oracle/asm_init.ora';
File created.
From here, questions arise.
I will restart intance using new spfile.
SQL> shutdown ;
ASM diskgroups volume disabled
ASM diskgroups dismounted
ASM instance shutdown
SQL>
I'll check for init files in the directory $CRS_HOME/dbs
ls /u01/app/11.2.0/grid_crs/dbs
ab_+ASM1.dat
hc_+ASM1.dat
No init file...both nodes
Now I will start the ASM instance with new SPFILE.
SQL> startup
ASM instance started
Total System Global Area 283930624 bytes
Fixed Size 2212656 bytes
Variable Size 256552144 bytes
ASM Cache 25165824 bytes
ASM diskgroups mounted
ASM diskgroups volume enabled
SQL> show parameter spfile
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
spfile string +DATA/asm/asmparameterfile/registry.253.732993435
The more interesting than the second node was also the instance with dummy .. just restarting the ASM instance in second node he finds SPFILE.
In GPnP ... no SPFILE
$srvctl config asm
ASM home: /u01/app/11.2.0/grid_crs
ASM listener: LISTENER
Docs said. ...
When an Oracle ASM instance searches for an initialization parameter file, the search order is:
1.The location of the initialization parameter file specified in the Grid Plug and Play (GPnP) profile
2.If the location has not been set in the GPnP profile, the search order changes to:
1. SPFILE in the Oracle ASM instance home
For example, the SPFILE for Oracle ASM has the following default path in the Oracle grid infrastructure home in a Linux environment:
$ORACLE_HOME/dbs/spfile+ASM.ora
2. PFILE in the Oracle ASM instance home
Questions ...
How ASM 11g find the path of the SPFILE?
When we run the CREATE SPFILE he records the path of the SPFILE in somewhere?
How ASM reads the SPFILE that inside of a DG who theoretically was not mounted?