Oracle RAC File System:
DB Instance status
. db_env
SQL> select inst_id,instance_number,status,instance_name from gv$instance;
gv$database - Db up and running.
SQL> select inst_id,name,open_mode from gv$database;
Using srvctl - tool - manage database resources
$srvctl status database -d prod
Finding instance status in RAC
$ srvctl status instance -d prod -i prod1
How to start/stop/status - instance in RAC
$ srvctl stop instance -d prod -i prod2
$ srvctl status instance -d prod -i prod1,prod2
$ srvctl start instance -d prod -i prod2
To shutdown database and all instances
$srvctl stop database -d prod -o immediate
$srvctl start database -d prod -o open
$ srvctl config database -d prod
RAC files:
In rac, using OMF concept (oracle managed files) . Oracle will assign
the file name and location to store in asm.
using parameter db_create_file_dest
sql>show parameter db_create_file_dest
db_create_file_dest string +DATA
+DATA is the diskgroup associated with disks physically in ASM.
setting this parameter, oracle will store files in diskgroup
default.
Creating tablespace :
sql>select file_name from dba_data_files;
sql>select tablespace_name from dba_tablespaces;
sql>create tablespace utbs datafile '/oradata/prod/ctbs01.dbf' size
100m autoextend on maxsize unlimited;
using diskgroups
sql>create tablespace ractbs;
sql>create tablespace ctbs datafile '+DATA' size 100m autoextend on maxsize unlimited;
sql>alter tablespace ctbs add datafile '+DATA' size 100m;
sql>alter tablespace ctbs add datafile '+DATA';
SQL> drop tablespace CTBS including contents and datafiles;
sql>show parameter db_create_file_dest
+DATA
SQL> create tablespace ractbs;
sql>select
file_name,autoextensible,bytes/1024/1024,maxbytes/1024/1024 from
dba_data_files where tablespace_name like 'CTBS';
default 100m , auto,max32gb
or else , we can explicity use the location with .dbf
sql>create tablespace mtbs datafile '+DATA/prod/datafile/catbs01.dbf'
size 100m;
Adding datafiles:
sql>alter tablespace ractbs add datafile '+DATA' size 100m autoextend
on maxsize unlimited;
with out
sql>alter tablespace ractbs add datafile
'+DATA/prod/datafile/ractbs03.dbf' size 100m;
For Undo Management :
purpose : to hold old images for read consistency
Every instance has own undo tablespace
rac1 - prod1 - undoractbs1
rac2 - prod2 - undoractbs2
define retention of every instance independently
or using sid='*' applicable for all instances.
sql>select tablespace_name from dba_tablespaces where tablespacE_name like 'UNDO%';
Adding datafile for undo
sql>alter tablespace undotbs1 add datafile '+DATA' size 100m;
SQL> select tablespace_name from dba_tablespaces where tablespace_name like 'UNDO%';
or
sql>alter tablespace undoractbs1 add datafile;
or
sql>create undo tablespace undoractbs3;
Login to instance prod1, same in other instances.
sql>show parameter undo_tablespace
sql>show parameter undo_retention
Redo Management
using parameter db_create_online_log_dest_1=+DATA
db_create_online_log_dest_2=+FRA
set the destination of redo using OMF
redo is associated with every instance with thread#
thread# from gv$instance
Redo groups are created independently for every instance.
each Instance has default two redo groups
SQL> select thread#,instance_number,instance_name from gv$instance;
sql>select thread#,group#,bytes/1024/1024,members from gv$log
Maintain same number of group# and size of every instance logs.
SQL> column REDOLOG_FILE_NAME format a50;
SQL> set lines 1000
SQL> SELECT a.GROUP#, a.THREAD#, a.SEQUENCE#,
a.ARCHIVED, a.STATUS, b.MEMBER AS REDOLOG_FILE_NAME,
(a.BYTES/1024/1024) AS SIZE_MB FROM v$log a
JOIN v$logfile b ON a.Group#=b.Group#
ORDER BY a.GROUP#;
SQL> ALTER DATABASE ADD LOGFILE THREAD 1
GROUP 5 '+DATA' SIZE 100m,
GROUP 6 '+FRA' SIZE 100m;
SQL>
SQL> ALTER DATABASE ADD LOGFILE THREAD 2
GROUP 7 '+DATA' SIZE 100m,
GROUP 8 '+FRA' SIZE 100m;
5-8groups approc each instance. with 2gb each member
Enable Archivelogs - FRA diskgroup
Configure +FRA- by adding diskgroups using asmca or sql>
alter system set db_recovery_file_dest_size=5G scope=both sid='*';
alter system set db_recovery_file_dest='+DATA' scope=both sid='*';
bring down db and do the change in any one of the instance of a db.
$srvctl stop database -d prod
on rac1
sql>startup mount
or
$srvctl start instance -d prod -i prod1 -o mount
sql>alter database archivelog;
sql>alter database open;
$srvctl start instance -d prod -i prod2,prod3
RAC - DB files
using db_create_file_dest parameter will set the diskgroup
so can create tablespace / add datafile with out specifying the filename/location.
will auto allocate the file name with file number in diskgroup configured globally.
using OMF concept.(oracle managed files).
eg: +DATA
db_create_file_dest=+DATA
. db_env
sql>create tablespace rtbs;
asmcmd>ls
a file number is associated with every asm file when added as per OMF.
Redo/Undo
Abt redo and undo are independent associated with that instance.
If rac1 - then using thread# - redo and undo are associated.
1 1,2 undoractbs1
rac2 - then using thread#
2 3,4 undoractbs2
rac3 - 3 5,6 undoractbs3
so add new 9 redo groups each instance with min 3 with size 1/2G
Unix level , can start/stop/status of instance/db using srvctl.
Note :Info on Oracle RAC Files it may be differ from your environment production,testing,development and naming conventions etc,Unix level , can start/stop/status of instance/db using srvctl.
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