Interview Questions.

Question 1. What Is The Major Difference Between 10g And 11g Rac?

Answer :

Well, there is not a great deal distinction among 10g and 11gR (1) RAC.

But there may be a great difference in 11gR2.

Prior to 11gR1 (10g) RAC, the subsequent had been managed by means of Oracle CRS:

Databases
Instances
Applications
Node Monitoring
Event Services
High Availability
From 11gR2 (onwards) it’s completed HA stack coping with and providing the following resources as like the different cluster software like VCS and so forth.

Databases
Instances
Applications
Cluster Management
Node Management
Event Services
High Availability
Network Management (gives DNS/GNS/MDNSD offerings on behalf of other conventional offerings) and SCAN – Single Access Client Naming approach, HAIP.
Storage Management (with help of ASM and other new ACFS filesystem).
Time synchronization (alternatively relying upon conventional NTP).
Removed OS dependent hold checker and so forth, manages with own additional monitor method.
Question 2. What Are Oracle Cluster Components?

Answer :

Cluster Interconnect (HAIP)
Shared Storage (OCR/Voting Disk)
Cluster ware software
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Question three. What Are Oracle Rac Components?

Answer :

VIP, Node apps and so on.

Question four. What Are Oracle Kernel Components (nothing But How Does Oracle Rac Database Differs Than Normal Single Instance Database In Terms Of Binaries And Process)?

Answer :

Basically Oracle kernel need to switched on with RAC On option whilst you exchange to RAC, that is the difference because it helps few RAC bg technique like LMON, LCK, LMD, LMS and many others.

To turn on RAC:

# hyperlink the oracle libraries
$ cd $ORACLE_HOME/rdbms/lib
$ make -f ins_rdbms.Mk rac_on
# rebuild oracle
$ cd $ORACLE_HOME/bin
$ relink oracle
Oracle RAC consists of  or more database times. They are composed of Memory structures and history procedures equal as the unmarried instance database. Oracle RAC instances use two strategies GES(Global Enqueue Service), GCS(Global Cache Service) that allow cache fusion.

Oracle RAC times are composed of following history strategies:

ACMS—Atomic Controlfile to Memory Service (ACMS)
GTX0-j—Global Transaction Process
LMON—Global Enqueue Service Monitor
LMD—Global Enqueue Service Daemon
LMS—Global Cache Service Process
LCK0—Instance Enqueue Process
RMSn—Oracle RAC Management Processes (RMSn)
RSMN—Remote Slave Monitor
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Question 5. What Is Cluster Ware?

Answer :

Software that provides various interfaces and offerings for a cluster. Typically, this consists of abilties that:

Allow the cluster to be controlled as a whole.
Protect the integrity of the cluster.
Maintain a registry of resources throughout the cluster.
Deal with adjustments to the cluster.
Provide a commonplace view of assets.
Oracle 11g Interview Questions
Question 6. What Is Gns?

Answer :

Grid Naming carrier is opportunity carrier to DNS , for you to act as a sub area for your DNS however controlled via Oracle, with GNS the relationship is routed to the cluster IP and manages internally.

Question 7. List Key Benefits Of Asm?

Answer :

Stripes files instead of logical volumes.
Provides redundancy on a document basis.
Enables on line disk reconfiguration and dynamic rebalancing.
Reduces the time significantly to resynchronize a brief failure through monitoring changes even as disk is offline.
Provides adjustable rebalancing pace.
Is cluster-aware.
Supports analyzing from mirrored replica rather than number one copy for prolonged clusters.
Is robotically established as a part of the Grid Infrastructure.
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Question 8. What Is Node Listener?

Answer :

In 11gr2 the listeners will run from Grid Infrastructure software domestic

The node listener is a method that facilitates set up community connections from ASM clients to the ASM instance.
Runs with the aid of default from the Grid $ORACLE_HOME/bin listing.
Listens on port 1521 by using default.
Is similar to a database example listener.
Is able to listening for all database times at the same gadget in addition to the ASM instance.
Can run concurrently with separate database listeners or be replaced by using a separate database listener.
Is named tnslsnr at the Linux platform.
Question 9. What Is Scan Listener?

Answer :

A scan listener is some thing that additional to node listener which listens the incoming db connection requests from the client which were given through the test IP, it were given endpoints configured to node listener where it routes the db connection requests to unique node listener.

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Question 10. What Is The Difference Between Crsctl And Srvctl?

Answer :

Crsctl manages cluster ware-related operations:

Starting and preventing Oracle Cluster ware.
Enabling and disabling Oracle Cluster ware daemons.
Registering cluster assets.
Srvctl manages Oracle useful resource–related operations:

Starting and stopping database times and offerings.
Also from 11gR2 manages the cluster resources like community, vip, disks and so on.
Question 11. How To Control Oracle Cluster Ware?

Answer :

To begin or stop Oracle Cluster ware on a particular node:

# crsctl forestall crs
# crsctl begin crs
To allow or disable Oracle Cluster ware on a particular node:

# crsctl enable crs
# crsctl disable crs
Oracle RAC/ASM Interview Questions
Question 12. How To Check The Cluster (all Nodes) Status?

Answer :

To take a look at the viability of Cluster Synchronization Services (CSS) throughout nodes:

$ crsctl check cluster

CRS-4537: Cluster Ready Services is online.

CRS-4529: Cluster Synchronization Services is online.

CRS-4533: Event Manager is on line.

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Question 13. How To Check The Cluster (one Node) Status?

Answer :

$ crsctl test crs

CRS-4638: Oracle High Availability Services is on line.

CRS-4537: Cluster Ready Services is online.

CRS-4529: Cluster Synchronization Services is on-line.

CRS-4533: Event Manager is online.

Question 14. How To Find Location Of Ocr?

Answer :

cat /and so on/oracle/ocr.Loc
ocrconfig neighborhood=+DATA

local_only=FALSE

#OCRCHECK (additionally about OCR integrity)
Question 15. What Is Asm Striping?

Answer :

ASM can use variable size facts extents to support large files, lessen reminiscence requirements, and enhance overall performance.

Each information extent resides on an person disk.
Data extents consist of one or greater allocation devices.
The statistics volume size is:

Equal to AU for the primary 20,000 extents (zero–19999)
Equal to 4 × AU for the following 20,000 extents (20000–39999)
Equal to 16 × AU for extents above forty,000
ASM stripes files the use of extents with a rough approach for load balancing or a satisfactory method to reduce latency.

Coarse-grained striping is continually equal to the powerful AU length.
Fine-grained striping is usually equal to 128 KB.
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Question 16. How Many Asm Disk Groups Can Be Created Under One Asm Instance?

Answer :

ASM imposes the subsequent limits:

63 disk groups in a storage device
10,000 ASM disks in a garage device
Two-terabyte most garage for each ASM disk (non-Exadata)
Four-petabyte most garage for each ASM disk (Exadata)
40-exabyte most garage for every storage machine
1 million files for each disk institution
ASM file length limits (database restrict is 128 TB):

External redundancy most record size is a hundred and forty PB.
Normal redundancy maximum report length is forty two PB.
High redundancy maximum file length is 15 PB.
Question 17. How To Change Cluster Interconnect In Rac?

Answer :

On a unmarried node in the cluster, upload the new international interface specification:

$ oifcfg setif -international eth2/192.0.2.Zero:cluster_interconnect
Verify the adjustments with oifcfg getif and then prevent Cluster ware on all nodes via jogging the following command as root on every node:

# oifcfg getif
# crsctl stop crs
Assign the community address to the new community adapters on all nodes using ifconfig:

#ifconfig eth2 192.Zero.2.15 netmask 255.255.255.0 broadcast 192.0.2.255
Remove the previous adapter/subnet specification and restart Cluster ware:

$ oifcfgdelif -global eth1/192.168.1.0
# crsctl start crs
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Question 18. Managing Or Modifying Scan In Oracle Rac?

Answer :

To upload a SCAN VIP aid:

$ srvctl add test -n cluster01-experiment
To cast off Cluster ware resources from SCAN VIPs:

$ srvctl remove scan [-f]
To upload a SCAN listener aid:

$ srvctl upload test listener
$ srvctl add scan listener -p 1521
To get rid of Cluster ware resources from all SCAN listeners:

$ srvctl remove experiment listener [-f]
Oracle 11g Interview Questions
Question 19. How To Check The Node Connectivity In Oracle Grid Infrastructure?

Answer :

$ cluvfy comp nodecon -n all –verbose

Question 20. Can I Stop All Nodes In One Command? Meaning That Stopping Whole Cluster?

Answer :

In 10g its now not possible, in which in 11g it's far feasible

[root@pic1]# crsctl begin cluster -all

[root@pic2]# crsctl forestall cluster –all

Oracle Real Application Clusters Interview Questions
Question 21. What Is Olr? Which Of The Following Statements Regarding The Oracle Local Registry (olr) Is True?

Answer :

Each cluster node has a nearby registry for node-precise resources.
The OLR have to be manually created after installing Grid Infrastructure on every node in the cluster.
One of its capabilities is to facilitate Cluster ware startup in conditions wherein the ASM shops the OCR and balloting disks.
You can test the repute of the OLR the usage of ocrcheck.
Question 22. What Is Runfixup.Sh Script In Oracle Cluster Ware 11g Release 2 Installation?

Answer :

With Oracle Cluster ware 11g release 2, Oracle Universal Installer (OUI) detects whilst the minimal requirements for an installation are not met, and creates shell scripts, known as fixup scripts, to complete incomplete system configuration steps. If OUI detects an incomplete assignment, then it generates fixup scripts (runfixup.Sh). You can run the fixup script once you click on the Fix and Check Again Button.

The Fixup script does the following:

If essential sets kernel parameters to values required for successful set up, consisting of:

Shared reminiscence parameters.
Open file descriptor and UDP ship/get hold of parameters.
Sets permissions on the Oracle Inventory (vital stock) listing. Reconfigures primary and secondary institution memberships for the installation proprietor, if important, for the Oracle Inventory directory and the working device privileges agencies.

Sets shell limits if vital to required values.
Question 23. How To Stop Whole Cluster With Single Command?

Answer :

crsctl prevent cluster (possible handiest from 11gr2), please be aware crsctl instructions will become worldwide now, in case you do not specify node mainly the command completed globally

as an instance:

crsctl prevent crs (stops in all crs resource in all nodes).
Crsctl forestall crs –n <neonate) (stops handiest in certain node).
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Question 24. Crs Is Not Starting Automatically After A Node Reboot, What You Do To Make It Happen?

Answer :

crsctl allow crs (as root)

to disable

crsctl disable crs (as root)

Oracle SOA fit 11g Interview Questions
Question 25. Can You Add Voting Disk Online? Do You Need Voting Disk Backup?

Answer :

Yes, as consistent with documentation, when you have multiple balloting disk you can add online, however if you have only one vote casting disk, by way of that cluster might be down as its misplaced you just want to begin crs in special mode and add the vote disk using

crsctl add vote disk <path>

Question 26. You Have Lost Ocr Disk, What Is Your Next Step?

Answer :

The cluster stack may be down due to the truth that cssd is not able to keep the integrity, that is real in 10g, from 11gR2 onwards, the crsd stack may be down, the house nevertheless up and walking. You can add the OCR back by restoring the automatic backup or import the manual backup.

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