1 Patterns
Oracle 12c Flex ASM & Flex Cluster
PRESENTER
Yenugula Venkata Ravikumar OCM, Head-Database Practice, Patterns
23rd AUGUST 2014 HYDERABAD, INDIA
2 Patterns
AB
OU
T M
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3 Patterns
AGENDA
The History of ASM Benefits Of ASM Automatic Storage Management (ASM) Overview Flex ASM Flex Cluster Oracle 10g R2 Functionality Oracle 11g R2 Functionality Oracle 12c R1 Functionality ASM Cluster ASM Network ASM Remote Access Deploying the Flex ASM
4 Patterns
HISTORY OF ASM
Before Oracle 10g, Storage Management was provided by 3rd parties
CUSTOMER CHALLENGES
• Large databases required considerable storage management • Best performance required raw storage • NFS solutions, while simple, did not perform as well as raw • For RAC, cluster file systems were not available
With Oracle 10g, ASM provided
• Simplicity of management, even better than NFS solutions • Performance equal to raw disks • Support for RAC clusters
THE SIMPLE IDEA OF ASM
• Integrated volume manager and file system • Stripe and mirror files across disks in a ASM Disk Group • Automatic “Rebalance” • Built on the Oracle instance architecture • Manage storage as a global cluster “Shared Disk Groups”
5 Patterns
BENEFITS OF ASM (1 of 2)
I/O is spread evenly across all available disk drives to prevent hot spots and
maximize performance
Inherent large file supports
Performs automatic online redistribution after the incremental addition or removal of storage capacity
Maintains redundant copies of data to provide high availability or leverage 3rd party RAID functionality
Supports Oracle Database as well as Oracle Real Application Clusters (RAC)
6 Patterns
BENEFITS OF ASM (2 of 2)
For simplicity and easier migration to ASM, an Oracle Database can contain ASM and non-ASM files. Any new files can be created as ASM files whilst existing files can also be migrated to ASM
RMAN commands enable non-ASM managed files to be relocated to an ASM disk group
Oracle Enterprise Manager can be used to manage ASM disk and file management activities
ASM reduces Oracle Database cost and complexity without compromising performance or availability
7 Patterns
ARCHITECTURE OF ASM
OPERATING SYSTEM
HARDWARE
Oracle Database
ASM
File System & Volume Management
OPERATING SYSTEM
HARDWARE
Logical Volume Manager
File System
ORACLE DATABASE
8 Patterns
Oracle RAC 10gR2 CONFIGURATION
9 Patterns
Oracle RAC 11gR2 CONFIGURATION
10 Patterns
CAPABILITIES OF ASM
1-1 ASM to SERVER
Disk1 Disk 2 Disk 3 Disk 4 Disk 5 Disk 6 Disk 7
Disk Group A Disk Group B
Database Database Database
File 1 File 2
File 3 File 4
ASM Cluster Pool of Storage
Oracle
RAC
Servers
ASM
Instance
ASM
Instance
ASM
Instance
ASM
Instance
ASM
Instance
Database
Instance
Database
Instance
Database
Instance
Database
Instance
Database
Instance
SHARED DISK GROUPS
WIDE FILE STRIPING
11 Patterns
AUTOMATIC STORAGE MANAGEMENT (ASM) OVERVIEW
Current State
ASM Cluster Pool of Storage
Disk Group B Disk Group A SHARED DISK GROUPS WIDE FILE STRIPING
ONE TO ONE MAPPING OF ASM INSTANCES TO SERVERS
ASM Instance
Database Instance
ASM Disk
RAC CLUSTER
Node4 Node3 Node2 Node1 Node5 ASM ASM ASM ASM ASM
ASM Instance
Database Instance
DBA DBA DBB DBB DBC DBB
12 Patterns
Oracle RAC 11gR2 CONFIGURATION
Current Challenge – Oracle RAC 11gR2
4 Node
WAN TRAFFIC
CLIENTS
Primary Site
+ASM1 +ASM2 +ASM3 +ASM4
Loss of Service If ASM on any node fails Database service is down
13 Patterns
Oracle Database 11gR2 with ASM
login as: oracle
[email protected]’s password: ******** Last login: Fri Sep 27 06:05:44 2013
[oracle@rac1 ~]$ ps -ef | grep pmon
oracle 3053 1 0 05:56 ? 00:00:00 asm_pmon_+ASM1
oracle 3849 1 0 05:57 ? 00:00:00 ora_pmon_flavia1
[oracle@rac1 ~]$ srvctl status asm
ASM is running on rac2,rac1
[oracle@rac1 ~]$ crsctl check cluster
CRS-4537: Cluster Ready Services is online
CRS-4529: Cluster Synchronization Services is online
CRS-4533: Event Manager is online
[oracle@rac1 ~]$ srvctl stop asm -n rac1 -o abort -f
LOG INTO RAC DATABASE INSTANCE (RAC1)
CHECK STATUS OF ASM & RAC DATABASE INSTANCES
CHECK STATUS OF ASM INSTANCE IN RAC DATABASE INSTANCES1 (RAC1)
CHECK STATUS OF CLUSTER IN RAC DATABASE INSTANCES1 (RAC1)
STOP THE ASM INSTANCE IN RAC DATABASE INSTANCE1
(RAC1)
14 Patterns
Oracle Database 11gR2 with ASM
[oracle@rac1 ~]$ srvctl stop asm -n rac1 -o abort -f
[oracle@rac1 ~]$ srvctl status asm
CHECK THE STATUS OF ASM INSTANCE IN RAC DATABASE INSTANCE1 (RAC1)
15 Patterns
Oracle Database 11gR2 with ASM
[oracle@rac1 ~]$ srvctl stop asm -n rac1 -o abort -f
[oracle@rac1 ~]$ srvctl status asm
ASM is running on rac2
16 Patterns
Oracle Database 11gR2 with ASM
[oracle@rac1 ~]$ srvctl stop asm -n rac1 -o abort -f
[oracle@rac1 ~]$ srvctl status asm
ASM is running on rac2
[oracle@rac1 ~]$ ps -ef | grep pmon
CHECK THE STATUS OF ASM & RAC DATABASE INSTANCE (RAC1)
17 Patterns
Oracle Database 11gR2 with ASM
[oracle@rac1 ~]$ srvctl stop asm -n rac1 -o abort -f
[oracle@rac1 ~]$ srvctl status asm
ASM is running on rac2
[oracle@rac1 ~]$ ps -ef | grep pmon
oracle 7885 5795 0 06:20 pts/0 00:00:00 grep pmon
SUMMARY
The database instance is strongly linked to the ASM instance If an ASM instance fails so will the database instance on the
same node
18 Patterns
FLEX ASM: ELIMINATE 1:1 SERVER MAPPING
New: ASM Storage Consolidation in Oracle Database 12c
ASM Cluster Pool of Storage
Disk Group B Disk Group A SHARED DISK GROUPS WIDE FILE STRIPING
DATABASES SHARE ASM INSTANCES
ASM Instance
Database Instance
ASM Disk
RAC Cluster
Node5 Node4 Node3 Node2 Node1
Node5 runs as ASM Client to Node4
Node1 runs as ASM Client to Node2
Node1 runs as ASM Client to Node4
Node2 runs as ASM Client to Node3
ASM ASM ASM
ASM Instance
DBA DBA DBB DBB DBC DBB
19 Patterns
Oracle Database 12cR1 with FLEX ASM
[oracle@oel6-112-rac1 Desktop]$ hostname
[oracle@oel6-112-rac1 Desktop]$ ps -ef | grep pmon
oracle 3325 1 0 17:39 ? 00:00:00 asm_pmon_+ASM1
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
[oracle@oel6-112-rac1 Desktop]$ srvctl status asm
ASM is running on oel6-112-rac2,oel6-112-rac1
oel6-112-rac1.localdomain
[oracle@oel6-112-rac1 Desktop]$ crsctl check cluster
CRS-4537: Cluster Ready Services is online
CRS-4529: Cluster Synchronization Services is online
CRS-4533: Event Manager is online
[oracle@oel6-112-rac1 Desktop]$ asmcmd
ASMCMD> showclustermode
LOG INTO RAC DATABASE INSTANCE 1 (RAC1)
CHECK THE STATUS OF ASM & RAC DATABASE INSTANCES
CHECK THE STATUS OF ASM INSTANCE IN RAC DATABASE INSTANCE FROM
INSTANCE 1 (RAC 1)
CHECK THE STATUS OF CLUSTER IN INSTANCE 1 (RAC 1)
CHECK IF ORACLE FLEX ASM IS ENABLED OR NOT (RAC1)
20 Patterns
Oracle Database 12cR1 with FLEX ASM
[oracle@oel6-112-rac1 Desktop]$ asmcmd
ASMCMD> showclustermode
ASM cluster : Flex mode enabled ASMCMD> showclusterstate
21 Patterns
Oracle Database 12cR1 with FLEX ASM
[oracle@oel6-112-rac1 Desktop]$ asmcmd
ASMCMD> showclustermode
ASM cluster : Flex mode enabled ASMCMD> showclusterstate
Normal ASMCMD> exit
[oracle@oel6-112-rac1 Desktop]$ srvctl status asm -detail
CHANGE CARDINALITY OF THE ASM (RAC 1)
22 Patterns
Oracle Database 12cR1 with FLEX ASM
[oracle@oel6-112-rac1 Desktop]$ asmcmd
ASMCMD> showclustermode
ASM cluster : Flex mode enabled ASMCMD> showclusterstate
Normal ASMCMD> exit
[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
23 Patterns
Oracle Database 12cR1 with FLEX ASM
[oracle@oel6-112-rac1 Desktop]$ asmcmd
ASMCMD> showclustermode
ASM cluster : Flex mode enabled ASMCMD> showclusterstate
Normal ASMCMD> exit
[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
[oracle@oel6-112-rac2 Desktop]$ asmcmd
CHECK IF ORACLE FLEX ASM IS ENABLED OR NOT (RAC2)
24 Patterns
Oracle Database 12cR1 with FLEX ASM
[oracle@oel6-112-rac1 Desktop]$ asmcmd
ASMCMD> showclustermode
ASM cluster : Flex mode enabled ASMCMD> showclusterstate
Normal ASMCMD> exit
[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
[oracle@oel6-112-rac2 Desktop]$ asmcmd
ASMCMD> showclustermode ASM cluster : Flex mode enabled ASMCMD> showclusterstate
25 Patterns
Oracle Database 12cR1 with FLEX ASM
Normal ASMCMD> exit
26 Patterns
Oracle Database 12cR1 with FLEX ASM
Normal ASMCMD> exit [oracle@oel6-112-rac2 Desktop]$ srvctl config asm -detail
CHANGE CARDINALITY OF THE ASM (RAC 2)
27 Patterns
Oracle Database 12cR1 with FLEX ASM
Normal ASMCMD> exit [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 [oracle@oel6-112-rac2 Desktop]$
28 Patterns
Oracle Database 12cR1 with FLEX ASM
Normal ASMCMD> exit [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 [oracle@oel6-112-rac1 Desktop]$ srvctl stop asm -node oel6-112-rac1 -stopoption abort -force
[oracle@oel6-112-rac1 Desktop]$ srvctl status asm PRCR-1070 : Failed to check if resource ora.asm is registered Cannot communicate with crsd [oracle@oel6-112-rac1 Desktop]$ crsctl check cluster
BRING DOWN THE ASM INSTANCE IN RAC DATABASE INSTANCE 1 (RAC 1)
CHECK STATUS OF ASM INSTANCE IN RAC DATABASE INSTANCE1 (RAC1)
CHECK STATUS OF CLUSTER SERVICES IN RAC DATABASE INSTANCE1 (RAC1)
29 Patterns
Oracle Database 12cR1 with FLEX ASM
Normal ASMCMD> exit [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 [oracle@oel6-112-rac1 Desktop]$ srvctl stop asm -node oel6-112-rac1 -stopoption abort -force
[oracle@oel6-112-rac1 Desktop]$ srvctl status asm PRCR-1070 : Failed to check if resource ora.asm is registered Cannot communicate with crsd [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
30 Patterns
Oracle Database 12cR1 with FLEX ASM
Normal ASMCMD> exit [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 [oracle@oel6-112-rac1 Desktop]$ srvctl stop asm -node oel6-112-rac1 -stopoption abort -force
[oracle@oel6-112-rac1 Desktop]$ srvctl status asm PRCR-1070 : Failed to check if resource ora.asm is registered Cannot communicate with crsd [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
[oracle@oel6-112-rac1 Desktop]$ ps -ef | grep pmon
CHECK STATUS OF ASM & RAC DATABASE IN INSTANCE1 (RAC 1)
31 Patterns
Oracle Database 12cR1 with FLEX 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 [oracle@oel6-112-rac1 Desktop]$ srvctl stop asm -node oel6-112-rac1 -stopoption abort -force
[oracle@oel6-112-rac1 Desktop]$ srvctl status asm PRCR-1070 : Failed to check if resource ora.asm is registered Cannot communicate with crsd [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
[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 in case due to some reason if the ASM instance was unable to be brought up/services goes down, still the database instance can be brought up as the database instance will look for ASM instance running in the same cluster.
[oracle@oel6-112-rac1 Desktop]$
32 Patterns
Oracle Database 12cR1 with FLEX ASM
[oracle@oel6-112-rac2 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
CHECK STATUS OF RAC DATABASE INSTANCE RUNNING WITHOUT ASM
INTANCE IN RAC DATABASE INSTANCE1 (RAC1)
33 Patterns
Oracle Database 12cR1 with FLEX ASM
[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.
SQL>
LOG INTO DATABASE INSTANCE FROM RAC DATABASE INSTANCE (RAC1)
34 Patterns
Oracle Database 12cR1 with FLEX ASM
SQL> select instance_name, instance_number from gv$instance;
INSTANCE_NAME INSTANCE_NUMBER
-------------------------------------------
orcl1 1
[oracle@oel6-112-rac1 Desktop]$ . 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
CONNECTING TO ASM INSTANCE OF RAC DATABASE INSTANCE2 (RAC2) FROM RAC
DATABASE INSTANCE1 (RAC1)
35 Patterns
Oracle Database 12cR1 with FLEX ASM
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>
SUMMARY
The database instance was using a dedicated ASM instance and that ASM instance was forced to stop working simulating a failure, so the database instance reconnected to an existent ASM instance on another node, for this example node 2 (rac2).
36 Patterns
SHARED DISK GROUPS WIDE FILE STRIPING
DATABASES SHARE ASM INSTANCES
FLEX ASM: SUPPORTING ORACLE DATABASE 11g
ASM Cluster Pool of Storage
Disk Group B Disk Group A
ASM Instance
Database Instance
ASM Disk
RAC CLUSTER
Node5 Node4 Node3 Node2 Node1 ASM ASM ASM
DBA DBA DBB DBB DBC DBB
ASM ASM
11.2 DB
11.2 DB
Previous Database versions will host Local ASM Instance
37 Patterns
Oracle FLEX CLUSTER
Comprises of a Hub and Leaf architecture
where in only the Hub nodes will only have
direct access to Oracle Cluster Registry
(OCR) and Voting Disk (VD)
However application can access the
database via Leaf nodes without ASM
instance NOT running on Leaf nodes
The connection to the database is through
Hub making it transparent for the
application
Depicts a typical Oracle flex cluster with four Leaf nodes and two Hub nodes. In a nutshell Oracle Flex Cluster requires Oracle Flex ASM.
38 Patterns
HUB NODES & LEAF NODES
Hub Nodes
They are connected among them via private network and have direct access to
the shared storage just like previous versions. These nodes are the ones that
access the Oracle Cluster Registry (OCR) and Voting Disk (VD) directly.
Leaf Nodes
These nodes are lighter and are not connected among them, neither access the
shared storage like the Hub Nodes. Each Leaf Node communicates with the Hub
Node that is attached to, and its connected to the cluster via the Hub Node that
is linked to.
39 Patterns
Oracle RAC 11gR2 CONFIGURATION
40 Patterns
Oracle 12c CONFIGURATION
41 Patterns
FLEX ASM & FLEX CLUSTER
Flex ASM Higher Availability (DB
instances can use remote ASM instances) • Planned or Unplanned
downtime
Reduces per-node ASM instance overhead • ASM only needs to run on 3
nodes in the cluster
Facilitates DB, Cluster & server consolidation
Multiple DB’s & applications in a cluster
Flex CLUSTER Less complex configuration and management for
non-database nodes Less complex configuration for Non-Database
nodes, such as Processing Nodes, Application / Web Server Nodes etc.
Node evictions NO LONGER REQUIRES a reboot - just a Clusterware restart
Cluster Health Monitor Improvements CHM repository now resides in an Oracle
DB known as the Grid Infrastructure Management Repository
Integrates with OEM for better management
42 Patterns
PREVIOUS ASM CLUSTER
ASM architecture utilized an ASM
instance on every server
Database instances dependent on
node-specific ASM instance
ASM overhead scaled with size of
cluster
Cluster reconfiguration events
increased with number of servers in a
cluster
DB1 DB2 DB3
ASM
DB1 DB2 DB4
ASM
DB1 DB5 DB4
ASM
DB1 DB5 DB6
ASM
Server Server
Server Server
Cluster
43 Patterns
NEW ASM CLUSTER
Eliminates requirement for an ASM instance on every cluster
server
Database instances connects to any ASM
instance in the cluster
Database instances can failover to a
secondary ASM instance
Administrators specify the cardinality of ASM
instances (default is 3)
Clusterware ensures ASM cardinality is maintained
ASM
Server Server Server Server
ASM
Server Server Server Server
ASM
Server Server Server Server
Cluster
44 Patterns
FLEX ASM NETWORK
In previous versions a CSS cluster requires:
A public network for client application access
One or more private networks for inter-node
communication within the cluster including
ASM traffic
Flex ASM adds the ASM network, which is
used for communication between ASM and its
clients
Can continue to share the CSS private network
45 Patterns
FLEX ASM REMOTE ACCESS
Remote Access
• In previous versions - ASM Clients use OS-authentication to connect to ASM
• This works because ASM Clients and Servers are always on the same server
With Oracle Database 12c:
ASM Clients and ASM Servers can be on different servers
A default configuration is created when the ASM cluster
is configured
Benefits of providing a shared password file in ASM Disk Group
46 Patterns
DEPLOYING FLEX ASM
Managing Flex ASM Flex ASM requires minimal monitoring and ongoing management
Primary objective is that instances are up and running
SRVCTL Command for: Checking ASM instance status Setting cardinality Starting – Stopping - and - Relocating ASM instances
No Flex ASM-specific instance parameters are required
Default settings will effectively support most situations
ASM server instances use automatic memory management
Oracle Flex ASM is managed by ASMCA, CRSCTL, SQL*Plus and SRVCTL
47 Patterns
NEW FLEX ASM
Flex Features
Increase maximum number of Disk Groups to 511 (Previous limit was 63)
Command for renaming ASM Disk
ASM Relocate Command Clients are automatically relocated to another instance if
an Oracle ASM instance fails When necessary, Clients can be manually relocated
using the ALTER SYSTEM RELOCATE CLIENT command
48 Patterns
New Option in Grid Infrastructure
Oracle ASM Deployment Model can be chosen during the installation of Oracle Grid Infrastructure
Oracle ASM Configuration Assistant (ASMCA) can be used to enable Oracle Flex ASM after the installation / upgrade is performed
The functionality is available only in an Oracle Grid Infrastructure Configuration
49 Patterns
Conversion of Standard Cluster to
Oracle Flex ASM Cluster
50 Patterns
51 Patterns
CHECK CLUSTER MODE AND CLUSTER STATE AFTER LOGGING INTO ASMCMD PROMPT
[oracle@racnroll1 ~]$ asmcmd
ASMCMD> showversion
ASM version : 12.1.0.1.0
ASMCMD> showclusterstate
Normal
ASMCMD> showclustermode
ASM cluster : Flex mode enabled
52 Patterns
Q&A Session
http://docs.oracle.com/ http://www.oracle.com/technetwork/es/articles/index.html
Refer for additional information yenugulavenkata.ravikumar
@yvrk1973
http://yvrk1973.blogspot.in
http://in.linkedin.com/pub/yv-ravikumar-oracle-certified-master-ocm/14/13/a50
Thanks for your time!