Interview Questions.

Q1. How To Check The Cluster (one Node) Status?

$ crsctl test crs

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

CRS-4537: Cluster Ready Services is on-line.

CRS-4529: Cluster Synchronization Services is on line.

CRS-4533: Event Manager is on line.

Q2. List Key Benefits Of Asm?

Stripes files in preference to logical volumes.

Provides redundancy on a document foundation.

Enables on line disk reconfiguration and dynamic rebalancing.

Reduces the time substantially to resynchronize a trient failure with the aid of tracking adjustments at the same time as disk is offline.

Provides adjustable rebalancing velocity.

Is cluster-aware.

Supports analyzing from reflected copy in preference to number one replica for prolonged clusters.

Is automatically established as a part of the Grid Infrastructure.

Q3. Can I Stop All Nodes In One Command? Meaning That Stopping Whole Cluster?

In 10g its not viable, where in 11g it is possible

[root@pic1]# crsctl start cluster -all

[root@pic2]# crsctl stop cluster –all

Q4. How To Find Location Of Ocr?

Cat /etc/oracle/ocr.Loc

ocrconfig neighborhood=+DATA

local_only=FALSE

#OCRCHECK (also about OCR integrity)

Q5. What Are Oracle Cluster Components?

Cluster Interconnect (HAIP)

Shared Storage (OCR/Voting Disk)

Cluster ware software program

Q6. How To Control Oracle Cluster Ware?

To start or forestall Oracle Cluster ware on a selected node:

# crsctl stop crs

# crsctl start crs

To allow or disable Oracle Cluster ware on a selected node:

# crsctl allow crs

# crsctl disable crs

Q7. Crs Is Not Starting Automatically After A Node Reboot, What You Do To Make It Happen?

Crsctl allow crs (as root)

to disable

crsctl disable crs (as root)

Q8. Can You Add Voting Disk Online? Do You Need Voting Disk Backup?

Yes, as according to documentation, when you have a couple of vote casting disk you could add on line, however if you have simplest one balloting disk, via that cluster can be down as its lost you simply want to start crs in distinct mode and upload the vote disk using

crsctl add vote disk <path>

Q9. What Is The Major Difference Between 10g And 11g Rac?

Well, there isn't a lot distinction between 10g and 11gR (1) RAC.

But there may be a great distinction in 11gR2.

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

Databases

Instances

Applications

Node Monitoring

Event Services

High Availability

From 11gR2 (onwards) it’s completed HA stack handling and presenting the subsequent resources as just like the different cluster software like VCS etc.

Databases

Instances

Applications

Cluster Management

Node Management

Event Services

High Availability

Network Management (offers DNS/GNS/MDNSD offerings on behalf of other conventional services) and SCAN – Single Access Client Naming technique, HAIP.

Storage Management (with assist of ASM and different new ACFS filesystem).

Time synchronization (rather depending upon traditional NTP).

Removed OS dependent cling checker and so on, manages with very own additional monitor procedure.

Q10. How To Check The Cluster (all Nodes) Status?

To test the viability of Cluster Synchronization Services (CSS) across nodes:

$ crsctl check cluster

CRS-4537: Cluster Ready Services is on line.

CRS-4529: Cluster Synchronization Services is online.

CRS-4533: Event Manager is online.

Q11. Managing Or Modifying Scan In Oracle Rac?

To add a SCAN VIP resource:

$ srvctl add scan -n cluster01-experiment

To cast off Cluster ware sources from SCAN VIPs:

$ srvctl eliminate test [-f]

To add a SCAN listener resource:

$ srvctl add experiment listener

$ srvctl add scan listener -p 1521

To dispose of Cluster ware assets from all SCAN listeners:

$ srvctl remove scan listener [-f]

Q12. What Is Cluster Ware?

Software that offers numerous interfaces and offerings for a cluster. Typically, this includes abilties that:

Allow the cluster to be managed as an entire.

Protect the integrity of the cluster.

Maintain a registry of sources throughout the cluster.

Deal with adjustments to the cluster.

Provide a common view of sources.

Q13. What Are Oracle Kernel Components (not anything But How Does Oracle Rac Database Differs Than Normal Single Instance Database In Terms Of Binaries And Process)?

Basically Oracle kernel want to switched on with RAC On alternative while you change to RAC, that is the difference because it enables few RAC bg process like LMON, LCK, LMD, LMS and many others.

To activate RAC:

# link 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 is composed of two or greater database instances. They are composed of Memory structures and historical past procedures identical because the unmarried example database. Oracle RAC instances use  procedures GES(Global Enqueue Service), GCS(Global Cache Service) that allow cache fusion.

Oracle RAC instances are composed of following background methods:

ACMS—Atomic Controlfile to Memory Service (ACMS)

GTX0-j—Global Traction 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

Q14. How To Change Cluster Interconnect In Rac?

On a unmarried node inside the cluster, upload the new global interface specification:

$ oifcfg setif -international eth2/192.0.2.0:cluster_interconnect

Verify the adjustments with oifcfg getif and then stop Cluster ware on all nodes by strolling the subsequent command as root on every node:

# oifcfg getif

# crsctl prevent crs

Assign the network deal with to the brand 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 former adapter/subnet specification and restart Cluster ware:

$ oifcfgdelif -worldwide eth1/192.168.1.0

# crsctl start crs

Q15. What Is Olr? Which Of The Following Statements Regarding The Oracle Local Registry (olr) Is True?

Each cluster node has a neighborhood registry for node-particular resources.

The OLR ought to be manually created after installing Grid Infrastructure on every node in the cluster.

One of its features is to facilitate Cluster ware startup in conditions wherein the ASM shops the OCR and vote casting disks.

You can test the popularity of the OLR the usage of ocrcheck.

Q16. What Is The Difference Between Crsctl And Srvctl?

Crsctl manages cluster ware-associated 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 preventing database instances and services.

Also from 11gR2 manages the cluster assets like community, vip, disks and many others.

Q17. What Is Asm Striping?

ASM can use variable size statistics extents to aid larger files, lessen reminiscence necessities, and improve performance.

Each records extent resides on an man or woman disk.

Data extents encompass one or extra allocation units.

The facts quantity length is:

Equal to AU for the primary 20,000 extents (zero–19999)

Equal to four × AU for the next 20,000 extents (20000–39999)

Equal to 16 × AU for extents above 40,000

ASM stripes files the use of extents with a rough method for load balancing or a fine technique to lessen latency.

Coarse-grained striping is constantly identical to the powerful AU length.

Fine-grained striping is usually identical to 128 KB.

Q18. What Is Scan Listener?

A test listener is something that extra to node listener which listens the incoming db connection requests from the consumer which were given thru the test IP, it were given endpoints configured to node listener where it routes the db connection requests to unique node listener.

Q19. What Is Gns?

Grid Naming provider is opportunity carrier to DNS , that allows you to act as a sub domain to your DNS but managed with the aid of Oracle, with GNS the connection is routed to the cluster IP and manages internally.

Q20. How To Check The Node Connectivity In Oracle Grid Infrastructure?

$ cluvfy comp nodecon -n all –verbose

Q21. How Many Asm Disk Groups Can Be Created Under One Asm Instance?

ASM imposes the following limits:

63 disk corporations in a storage gadget

10,000 ASM disks in a garage system

Two-terabyte most storage for every ASM disk (non-Exadata)

Four-petabyte most storage for every ASM disk (Exadata)

forty-exabyte most garage for each storage device

1 million files for every disk institution

ASM record length limits (database restrict is 128 TB):

External redundancy most record size is one hundred forty PB.

Normal redundancy most document size is forty two PB.

High redundancy most report length is 15 PB.

Q22. What Is Node Listener?

In 11gr2 the listeners will run from Grid Infrastructure software program home

The node listener is a manner that enables set up community connections from ASM clients to the ASM example.

Runs through 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 instances at the identical machine in addition to the ASM example.

Can run concurrently with separate database listeners or get replaced by a separate database listener.

Is named tnslsnr on the Linux platform.

Q23. What Is Runfixup.Sh Script In Oracle Cluster Ware 11g Release 2 Installation?

With Oracle Cluster ware 11g release 2, Oracle Universal Installer (OUI) detects while the minimum necessities for an set up are not met, and creates shell scripts, referred to as fixup scripts, to complete incomplete gadget configuration steps. If OUI detects an incomplete task, then it generates fixup scripts (runfixup.Sh). You can run the fixup script after you click the Fix and Check Again Button.

The Fixup script does the subsequent:

If essential units kernel parameters to values required for successful set up, which include:

Shared reminiscence parameters.

Open report descriptor and UDP ship/receive parameters.

Sets permissions at the Oracle Inventory (central inventory) directory. Reconfigures primary and secondary institution memberships for the installation proprietor, if vital, for the Oracle Inventory listing and the running device privileges groups.

Sets shell limits if essential to required values.

Q24. What Are Oracle Rac Components?

VIP, Node apps and so on.

Q25. How To Stop Whole Cluster With Single Command?

Crsctl prevent cluster (viable only from 11gr2), please notice crsctl instructions will become worldwide now, in case you do no longer specify node in particular the command achieved globally

as an instance:

crsctl stop crs (stops in all crs aid in all nodes).

Crsctl stop crs –n <neonate) (stops most effective in detailed node).

Q26. You Have Lost Ocr Disk, What Is Your Next Step?

The cluster stack can be down due to the reality that cssd is not able to preserve the integrity, that is proper in 10g, from 11gR2 onwards, the crsd stack can be down, the residence nonetheless up and running. You can upload the OCR back by restoring the automated backup or import the guide backup.